Year Percent 1950 9.16926 1955 8.25826 1960 8.8834 1965 10.29913 1970 11.85982 1975 12.51003 1980 11.26529 1985 10.96438 1990 13.91352 1995 16.53601 2000 18.25049 2005 18.33584 2010 20.18504 2015 22.35972 2020 24.60607 2025 26.54021 2030 27.74324 2035 29.31549 2040 30.98787 2045 32.68707 2050 34.14199 2055 34.86881 2060 35.79273 2065 35.88661 2070 36.56775 2075 37.02942 2080 37.15648 2085 37.12013 2090 37.08133 2095 37.07574 2100 37.17268