Year Percent 1950 27.86549 1955 26.59259 1960 25.52136 1965 24.6652 1970 25.25448 1975 27.32955 1980 29.58648 1985 31.91391 1990 33.52381 1995 33.35541 2000 33.33302 2005 33.0494 2010 32.43406 2015 32.35237 2020 31.43844 2025 30.16753 2030 28.71408 2035 27.15579 2040 25.8839 2045 24.55857 2050 23.44335 2055 22.54354 2060 21.80204 2065 21.25277 2070 20.83949 2075 20.53926 2080 20.33064 2085 20.18141 2090 20.08661 2095 20.03233 2100 19.99993