Year Percent 1950 14.30861 1955 15.83341 1960 16.39151 1965 16.07043 1970 15.62569 1975 16.58836 1980 18.13265 1985 19.64903 1990 22.75499 1995 24.97137 2000 27.43993 2005 30.86743 2010 32.23106 2015 31.7507 2020 29.57402 2025 25.91013 2030 23.2142 2035 23.22701 2040 24.28044 2045 25.91436 2050 27.55852 2055 26.30353 2060 24.84526 2065 23.92717 2070 23.64398 2075 24.34037 2080 24.66717 2085 24.39731 2090 23.703 2095 23.12184 2100 22.97233