Year Percent 1950 14.98881 1955 16.09834 1960 16.11048 1965 15.11864 1970 15.40325 1975 15.54594 1980 16.72289 1985 17.91982 1990 19.50107 1995 23.49224 2000 27.83051 2005 29.8498 2010 31.39077 2015 32.17929 2020 31.46809 2025 30.00276 2030 28.45407 2035 27.30245 2040 26.43872 2045 25.75097 2050 25.30446 2055 24.37579 2060 23.59363 2065 23.1544 2070 23.01729 2075 22.91146 2080 22.75502 2085 22.53694 2090 22.22906 2095 21.96318 2100 21.78163