Year Percent 1950 15.70962 1955 16.66167 1960 14.91562 1965 14.64092 1970 14.26114 1975 13.60585 1980 12.83987 1985 13.10328 1990 13.73059 1995 14.15159 2000 15.8617 2005 19.02985 2010 23.37126 2015 25.98153 2020 27.2906 2025 28.13232 2030 28.38117 2035 29.58101 2040 30.52952 2045 29.81248 2050 28.32091 2055 25.8881 2060 23.78024 2065 22.79324 2070 22.74328 2075 22.52478 2080 22.11849 2085 21.72651 2090 21.46538 2095 21.43695 2100 21.56478