The graph shows average life expectancy for males in the United States based on an individual's birth year. The average life expectancy for a man born in 1975 is 68.8 yr. The average life expectancy for a man born in 1995 is 72.5 yr. Assuming a linear trend, estimate the life expectancy for a man born in 1985. (Source: U.S. National Center for Health Statistics, www.cdc.gov/nchs).