May, 2013 cumulative flu vaccination rate for the 2012-2013 flu season. Vaccination coverage estimates by State National Immunization Survey (NIS) and Behavioral Risk Factor Surveillance System (BRFSS), 2012–13 influenza season.

Numbers reflect a 95% confidence interval with margin of error under 5 percent.

Source: https://www.cdc.gov/flu/fluvaxview/coverage-1213estimates.htm

Methodology: The data above was downlaoded Sept. 9 from the CDC as a spreadsheet, concatenated and refined using Python, then filtered and graphed with Javascript.