Year Percent 1950 15.39653 1955 16.54842 1960 15.61964 1965 15.87172 1970 16.27995 1975 17.7311 1980 19.6546 1985 20.17967 1990 21.15304 1995 22.72547 2000 24.25996 2005 26.05871 2010 27.63265 2015 27.77412 2020 28.13237 2025 29.04477 2030 29.82666 2035 30.41591 2040 29.62496 2045 27.95861 2050 25.92695 2055 24.55191 2060 24.34966 2065 24.49935 2070 24.82334 2075 24.54068 2080 23.94901 2085 23.42544 2090 23.23265 2095 23.34601 2100 23.48646