Year Percent 1950 17.62793 1955 16.85468 1960 15.15082 1965 14.55164 1970 14.7601 1975 14.91907 1980 15.38188 1985 16.27519 1990 16.85158 1995 16.61492 2000 17.90669 2005 20.05256 2010 21.86599 2015 20.85992 2020 22.15195 2025 24.5325 2030 27.32326 2035 30.20647 2040 31.38712 2045 30.24389 2050 27.02733 2055 23.87184 2060 21.70211 2065 21.4249 2070 22.75663 2075 23.43357 2080 23.43135 2085 22.38824 2090 21.30594 2095 21.02826 2100 21.50815