Year Percent 1950 13.53974 1955 14.05321 1960 14.39911 1965 14.80734 1970 15.19243 1975 15.40338 1980 15.64654 1985 15.97989 1990 17.07268 1995 18.53615 2000 21.73673 2005 23.30037 2010 23.88895 2015 24.62727 2020 25.54851 2025 25.84581 2030 25.40643 2035 24.91341 2040 23.84739 2045 23.74071 2050 24.64554 2055 25.16966 2060 25.33343 2065 24.60348 2070 23.44287 2075 22.88861 2080 22.79523 2085 22.89861 2090 22.82684 2095 22.39044 2100 21.78107