Year Percent 1950 11.07201 1955 10.55303 1960 11.53937 1965 13.17695 1970 15.21929 1975 16.16292 1980 15.45866 1985 16.54655 1990 20.74929 1995 23.41331 2000 25.01848 2005 25.25281 2010 27.14716 2015 29.08024 2020 31.25125 2025 33.23953 2030 34.46491 2035 35.93026 2040 37.40514 2045 38.78929 2050 39.83901 2055 40.14995 2060 40.65917 2065 40.43539 2070 40.83736 2075 41.05953 2080 40.98425 2085 40.78206 2090 40.61798 2095 40.53562 2100 40.57446