Year Percent 1950 27.5779 1955 27.35295 1960 26.73656 1965 40.0193 1970 46.45183 1975 55.49044 1980 58.94537 1985 52.90865 1990 47.1582 1995 50.6797 2000 51.0858 2005 58.788 2010 63.09061 2015 55.87304 2020 52.2474 2025 50.34441 2030 48.01614 2035 45.5667 2040 41.68777 2045 38.08861 2050 35.24586 2055 33.14099 2060 32.21539 2065 31.47717 2070 30.57789 2075 29.6075 2080 28.69794 2085 27.97282 2090 27.41477 2095 26.90974 2100 26.3547