Appears to be household: http://www.nytimes.com/interactive/2012/01/15/business/one-percent-map.html?_r=0 http://www.nytimes.com/interactive/2012/01/15/busines

Appears to be household: http://www.nytimes.com/interactive/2012/01/15/business/one-percent-map.html?_r=0 http://www.nytimes.com/interactive/2012/01/15/business/one-p... (That data is from 2012 though, so somewhat dated.)