Year Percent 1950 12.57756 1955 14.71041 1960 15.62853 1965 15.14185 1970 15.37111 1975 13.63745 1980 12.83511 1985 12.43953 1990 12.31663 1995 11.85164 2000 11.08267 2005 10.48532 2010 9.35861 2015 8.15515 2020 7.79975 2025 7.71382 2030 7.43675 2035 6.8875 2040 6.24736 2045 5.75509 2050 5.50847 2055 5.44787 2060 5.4064 2065 5.27816 2070 5.08296 2075 4.90411 2080 4.81092 2085 4.81351 2090 4.85111 2095 4.84956 2100 4.79014