Year Percent 1950 13.0164 1955 15.02762 1960 15.46315 1965 16.44877 1970 15.33226 1975 14.94647 1980 15.28734 1985 16.21196 1990 16.65339 1995 15.5683 2000 13.50052 2005 14.09344 2010 14.02252 2015 14.09887 2020 13.3401 2025 12.36817 2030 11.46384 2035 10.84242 2040 10.43182 2045 9.97101 2050 9.35184 2055 8.66608 2060 8.05857 2065 7.58951 2070 7.20425 2075 6.8619 2080 6.50586 2085 6.17702 2090 5.90299 2095 5.70105 2100 5.55048