I work at Rebuilding Together, a nonprofit which specializes in providing repairs and renovations to low income homeowners. For a while, we've been working with an internal fact sheet which depicts the estimated growth in the number of low income homeowners from 22.9 million in 2008 to 25.8 million in 2010. However, the person who worked out this estimate is no longer working with us and left no instructions or methodology behind how they found this number. They only wrote that they used ACS data based on an average household size of 2.68 people with a combined income below $44,700 as qualifying as low income. Does anyone have an idea of how I could work out the calculation that would yield this estimate? Beyond wanting to figure out if this number has any mathematical validity, we would like a reliable formula to use for making estimates about the change in number of low income households for administrative purposes.