Year Percent 1950 13.83827 1955 12.45609 1960 15.84121 1965 16.38609 1970 15.25061 1975 14.92129 1980 15.30499 1985 15.36552 1990 15.21095 1995 14.22195 2000 12.93408 2005 11.62381 2010 10.42696 2015 9.73159 2020 8.90267 2025 8.16207 2030 7.43992 2035 6.82388 2040 6.31457 2045 5.91584 2050 5.58088 2055 5.29228 2060 5.0486 2065 4.83633 2070 4.67992 2075 4.56354 2080 4.47665 2085 4.41961 2090 4.37123 2095 4.33378 2100 4.30559