Year Percent 1950 10.3973 1955 11.70535 1960 12.63592 1965 12.45782 1970 12.48582 1975 13.8752 1980 14.58307 1985 12.19173 1990 11.9772 1995 13.2686 2000 13.26625 2005 14.02972 2010 15.15157 2015 16.54104 2020 16.40318 2025 16.46956 2030 15.8659 2035 16.41747 2040 18.10469 2045 20.42628 2050 22.97565 2055 23.61437 2060 23.12932 2065 22.25283 2070 21.86233 2075 22.41123 2080 23.51247 2085 24.25478 2090 24.28096 2095 23.83643 2100 23.45006