Year Percent 1950 26.62145 1955 26.37624 1960 26.44135 1965 26.03399 1970 26.01187 1975 27.28792 1980 29.23293 1985 31.52422 1990 32.6663 1995 31.23351 2000 30.1057 2005 28.41421 2010 27.76636 2015 27.34373 2020 27.79432 2025 26.13766 2030 24.60783 2035 23.24805 2040 20.62259 2045 20.06386 2050 20.69796 2055 20.48196 2060 19.92225 2065 19.14108 2070 18.55203 2075 18.42224 2080 18.66561 2085 18.8858 2090 18.81872 2095 18.57075 2100 18.34836