Year Percent 1950 26.44158 1955 25.21114 1960 26.73677 1965 26.61546 1970 28.00431 1975 29.32528 1980 32.38413 1985 35.41099 1990 37.69826 1995 38.71309 2000 36.78659 2005 34.94703 2010 31.43913 2015 29.70148 2020 28.23597 2025 25.59288 2030 23.54462 2035 20.86487 2040 19.28971 2045 19.17656 2050 19.74612 2055 20.27111 2060 20.29256 2065 19.97806 2070 19.55686 2075 19.44216 2080 19.87338 2085 20.53368 2090 20.95626 2095 20.91451 2100 20.51431