Number of A/H1N1 influenza viruses sampled per locality, per clade (Figure 1).

Localities are listed in order of population size (*per 1,000 persons) and categorized as major cities (population of >1 million), mid-sized cities (population size of 100,000–999,999), or minor cities/towns (population of <99,999). Total number of isolates per locality listed in far right column.

居民点按人口规模（*以每千人计）排序，并划分为三类：大城市（人口＞100万）、中等城市（人口100000~999999）以及小型城市/城镇（人口＜99999）。各居民点的分离株总数均列于最右侧列中。