Wendover Productions explains basic economics of airline classes. The passengers in first class and business, assuming seats are occupied, make much more for airlines than the economy class. Sounds familiar.
Economics of airline class
Life expectancy changes
The data goes back to 1960 and up to the most current estimates for 2009. Each line represents a country.
Unemployment in America, Mapped Over Time
Watch the regional changes across the country from 1990 to 2016.