Year Percent 1950 28.75818 1955 27.66155 1960 25.92291 1965 24.26641 1970 23.17847 1975 23.81117 1980 24.6002 1985 25.94468 1990 27.3369 1995 28.85087 2000 30.47723 2005 31.40095 2010 33.72546 2015 28.05861 2020 28.35821 2025 31.34607 2030 31.989 2035 32.89809 2040 31.87462 2045 30.32017 2050 28.74583 2055 27.62178 2060 27.04996 2065 26.38689 2070 25.51004 2075 24.45463 2080 23.40709 2085 22.60503 2090 22.07693 2095 21.71299 2100 21.35813