Year Percent 1950 11.76122 1955 11.29638 1960 10.87858 1965 12.10676 1970 13.37138 1975 13.26702 1980 12.25227 1985 12.51439 1990 16.08024 1995 17.50539 2000 19.20019 2005 21.14443 2010 22.38633 2015 24.52958 2020 26.50219 2025 28.59911 2030 29.88504 2035 31.03049 2040 31.48051 2045 31.77912 2050 32.55647 2055 33.78205 2060 33.81905 2065 32.96511 2070 32.4878 2075 32.69972 2080 33.03925 2085 33.53952 2090 33.85625 2095 33.88944 2100 33.91383