Year Percent 1950 28.40674 1955 28.28765 1960 28.06682 1965 27.51213 1970 27.19825 1975 27.31189 1980 25.49145 1985 24.72332 1990 25.1252 1995 25.98828 2000 26.69875 2005 28.15171 2010 28.98118 2015 29.42172 2020 29.51799 2025 29.53236 2030 30.07702 2035 30.96034 2040 31.57039 2045 31.76978 2050 31.51146 2055 31.05783 2060 30.81264 2065 30.68401 2070 30.52607 2075 30.23112 2080 29.80166 2085 29.32612 2090 28.87755 2095 28.46736 2100 28.0724