Out-of-sample (leave-one-out) root mean-squared error (ORMSE) for each Poisson generalized additive model.

Values are normalized by the population size of each ZIP Code quartile and then multiplied by 106 to obtain ORMSE per one million residents. The rightmost column gives aggregate ORMSE across all ZIP Codes included in our study area. The quartiles contained: [0-8) (1st quartile), [8-12) (2nd quartile), [12-21) (3rd quartile), and >21 (4th quartile) percent of residents below the poverty line.

所有数值均先按照各邮政编码（ZIP Code）四分位组的人口规模进行归一化处理，随后乘以106，以计算得到每百万居民对应的ORMSE值。最右侧列展示了本研究区域内纳入的全部邮政编码分区的总ORMSE值。各四分位组对应的贫困人口占比区间分别为：[0-8)（第一四分位组）、[8-12)（第二四分位组）、[12-21)（第三四分位组）以及大于21%（第四四分位组）。