Over the past 70 years, disposable personal income in the US has increased by a factor of 116
Kantor, L. S. 1998. A Dietary Assessment of the U.S. Food Supply: Comparing Per Capita Food Consumption with Food Guide Pyramid Serving Recommendations. Economic Research Service, U. S. Department of Agriculture Agricultural Economics Report No. 772. http://www.ers.usda.gov/publications/aer772/.