Year Percent 1950 29.46315 1955 28.71683 1960 27.64396 1965 26.93835 1970 26.3519 1975 26.16057 1980 24.74059 1985 24.73069 1990 28.09573 1995 29.86246 2000 31.28739 2005 30.72947 2010 30.90863 2015 32.21436 2020 32.89226 2025 32.83534 2030 32.25095 2035 31.98657 2040 31.90032 2045 31.95822 2050 31.77778 2055 30.93339 2060 30.10188 2065 29.41874 2070 28.8712 2075 28.33641 2080 27.72094 2085 27.01751 2090 26.29555 2095 25.64345 2100 25.09499