I'm doing research for a YouTube video on CFS prevalence. Does anyone know the source of this figure? The last good prevalence data came from Leonard Jason's 1999 prevalance study which showed .42% of the US affected - which based on 1993 census data of the US population being 198 million comes to 800,000. That number has been extrapolated to "over a million" based on more a more recent US population of around 300 million. So where did the 17 million come from? Is that another extrapolation based on .42% times the world population of 1993? (The numbers don't add up unless you use a world population of 4 billion, which is way low for 1993.) Or did someone add up all of the various countries estimates of CFS? Where would someone even find this data?