Year Percent 1950 13.01305 1955 12.85559 1960 13.73105 1965 14.41077 1970 14.95079 1975 15.16664 1980 13.85506 1985 13.79745 1990 17.23242 1995 19.16472 2000 21.0575 2005 21.89012 2010 23.24694 2015 25.0995 2020 26.86898 2025 28.47233 2030 29.61335 2035 31.37761 2040 32.84369 2045 34.5108 2050 36.59568 2055 36.92264 2060 35.79727 2065 35.23508 2070 35.9102 2075 36.14744 2080 36.44027 2085 36.62218 2090 36.58831 2095 36.61891 2100 36.93928