2010-2014 ACS Median Age Variables - Boundaries

This layer contains 2010-2014 American Community Survey (ACS) 5-year data, and contains estimates and margins of error. The layer shows median age broken down by sex and race group. This is shown by tract, county, and state boundaries. There are also additional calculated attributes related to this topic, which can be mapped or used within analysis. This layer is symbolized to show the median age of the population. To see the full list of attributes available in this service, go to the "Data" tab, and choose "Fields" at the top right. Vintage: 2010-2014 ACS Table(s): B01001, B01002, B01002B, B01002C, B01002D, B01002E, B01002F, B01002G, B01002H, B01002I (Not all lines of ACS table B01001 are available in this feature layer.) Data downloaded from: Census Bureau's API for American Community Survey Date of API call: November 11, 2020 National Figures: data.census.gov The United States Census Bureau's American Community Survey (ACS): About the Survey Geography & ACS Technical Documentation News & Updates This ready-to-use layer can be used within ArcGIS Pro, ArcGIS Online, its configurable apps, dashboards, Story Maps, custom apps, and mobile apps. Data can also be exported for offline workflows. For more information about ACS layers, visit the FAQ. Please cite the Census and ACS when using this data. Data Note from the Census: Data are based on a sample and are subject to sampling variability. The degree of uncertainty for an estimate arising from sampling variability is represented through the use of a margin of error. The value shown here is the 90 percent margin of error. The margin of error can be interpreted as providing a 90 percent probability that the interval defined by the estimate minus the margin of error and the estimate plus the margin of error (the lower and upper confidence bounds) contains the true value. In addition to sampling variability, the ACS estimates are subject to nonsampling error (for a discussion of nonsampling variability, see Accuracy of the Data). The effect of nonsampling error is not represented in these tables. Data Processing Notes: This layer has associated layers containing the most recent ACS data available by the U.S. Census Bureau. Click here to learn more about ACS data releases and click here for the associated boundaries layer. The reason this data is 5+ years different from the most recent vintage is due to the overlapping of survey years. It is recommended by the U.S. Census Bureau to compare non-overlapping datasets. Boundaries come from the U.S. Census TIGER geodatabases. Boundary vintage (2014) appropriately matches the data vintage as specified by the Census. These are Census boundaries with water and/or coastlines clipped for cartographic purposes. For census tracts, the water cutouts are derived from a subset of the 2010 AWATER (Area Water) boundaries offered by TIGER. For state and county boundaries, the water and coastlines are derived from the coastlines of the 500k TIGER Cartographic Boundary Shapefiles. The original AWATER and ALAND fields are still available as attributes within the data table (units are square meters). The States layer contains 52 records - all U.S. states, Washington D.C., and Puerto Rico Census tracts with no population that occur in areas of water, such as oceans, are removed from this data service (Census Tracts beginning with 99). Percentages and derived counts, and associated margins of error, are calculated values (that can be identified by the "_calc_" stub in the field name), and abide by the specifications defined by the American Community Survey. Field alias names were created based on the Table Shells file available from the American Community Survey Summary File Documentation page. Negative values (e.g., -4444...) have been set to null, with the exception of -5555... which has been set to zero. These negative values exist in the raw API data to indicate the following situations: The margin of error column indicates that either no sample observations or too few sample observations were available to compute a standard error and thus the margin of error. A statistical test is not appropriate. Either no sample observations or too few sample observations were available to compute an estimate, or a ratio of medians cannot be calculated because one or both of the median estimates falls in the lowest interval or upper interval of an open-ended distribution. The median falls in the lowest interval of an open-ended distribution, or in the upper interval of an open-ended distribution. A statistical test is not appropriate. The estimate is controlled. A statistical test for sampling variability is not appropriate. The data for this geographic area cannot be displayed because the number of sample cases is too small.本图层包含2010-2014年美国社区调查（American Community Survey, ACS）5年期数据，涵盖各类估算值与误差边际。该图层展示了按性别与种族群体划分的人口中位年龄，以普查区（tract）、县（county）及州（state）边界为统计单元进行呈现。此外还包含与该主题相关的额外计算属性，可用于制图或分析工作。本图层通过符号化方式展示人口中位年龄。如需查看本服务中可用属性的完整列表，请访问「数据」选项卡，并选择右上角的「字段」选项。 数据版本：2010-2014年ACS 所用表格：B01001、B01002、B01002B、B01002C、B01002D、B01002E、B01002F、B01002G、B01002H、B01002I（本要素图层未包含ACS表格B01001的所有行数据） 数据下载自：美国人口普查局美国社区调查API API调用日期：2020年11月11日 全国数据来源：data.census.gov 美国人口普查局美国社区调查（ACS）：关于本调查 地理信息与ACS技术文档 新闻与更新 本现成可用的图层可在ArcGIS Pro、ArcGIS Online、其可配置应用、仪表板、Story Maps、自定义应用及移动应用中使用。数据也可导出用于离线工作流程。如需了解更多ACS图层相关信息，请访问常见问题解答（FAQ）页面。使用本数据时，请引用美国人口普查局及ACS。 美国人口普查局的数据说明：本数据基于抽样调查，存在抽样变异性。由抽样变异性导致的估算值不确定程度通过误差边际来体现。此处展示的为90%置信度的误差边际，其含义为：估算值减去误差边际与估算值加上误差边际所构成的区间（即置信上下限）有90%的概率包含真实数值。除抽样变异性外，ACS估算值还存在非抽样误差（关于非抽样变异性的讨论，请参见《数据的准确性》一文）。本表格未体现非抽样误差的影响。 数据处理说明：本图层附带了美国人口普查局发布的最新ACS数据关联图层。点击此处了解更多ACS数据发布信息，点击此处获取关联的边界图层。本数据与最新版本数据间隔5年以上，是由于调查年份存在重叠。美国人口普查局建议比较非重叠数据集。 边界数据源自美国人口普查局TIGER地理数据库。边界版本（2014年）与人口普查局指定的数据版本完全匹配。为满足制图需求，这些普查边界已裁剪掉水体及/或海岸线。对于普查区，水体裁剪范围源自TIGER提供的2010年AWATER（水域面积）边界的子集；对于州及县边界，水体及海岸线源自50万比例尺TIGER制图边界形状文件的海岸线。原始AWATER及ALAND字段仍可作为数据表格中的属性使用（单位：平方米）。 州图层包含52条记录——涵盖美国所有州、华盛顿特区及波多黎各。 本数据服务中移除了分布于海洋等水域区域且无人口的普查区（普查区编号以99开头）。 百分比及派生计数与相关误差边际均为计算值（可通过字段名中的「_calc_」前缀识别），并严格遵循美国社区调查的规范。 字段别名基于美国社区调查汇总文件文档页面中提供的表格框架文件创建。 除-5555…已被设为0外，其余负值（例如-4444…）均已被设为空值。这些负值在原始API数据中用于指示以下情形： 1. 误差边际列显示：无可用抽样观测值或抽样观测值过少，无法计算标准误及误差边际，因此不适合进行统计检验； 2. 无可用抽样观测值或抽样观测值过少，无法计算估算值；或由于其中一个或两个中位估算值落在开放分布的最低区间或最高区间，无法计算中位数比值； 3. 中位数落在开放分布的最低区间或最高区间，不适合进行统计检验； 4. 估算值已受控，不适合进行抽样变异性统计检验； 5. 由于抽样案例数量过少，无法展示该地理区域的数据。