Year Percent 1950 10.50933 1955 9.97186 1960 9.39153 1965 9.17887 1970 9.3421 1975 9.94886 1980 10.55498 1985 11.40897 1990 13.67901 1995 14.29374 2000 14.92448 2005 16.23279 2010 18.41685 2015 20.98703 2020 23.89261 2025 26.63239 2030 27.99877 2035 28.81658 2040 29.41073 2045 30.10764 2050 30.58976 2055 31.38925 2060 31.72236 2065 31.80598 2070 32.27671 2075 32.77105 2080 33.24918 2085 33.67567 2090 34.06907 2095 34.45237 2100 34.89535