Year Percent 1950 9.68602 1955 11.56589 1960 13.03165 1965 13.48038 1970 14.49118 1975 15.51753 1980 15.24833 1985 15.57802 1990 15.58624 1995 15.8143 2000 13.9035 2005 14.41966 2010 14.74621 2015 15.03118 2020 13.36053 2025 12.08111 2030 11.3178 2035 10.82742 2040 10.38379 2045 9.84442 2050 9.22806 2055 8.58878 2060 8.02648 2065 7.56737 2070 7.16733 2075 6.80367 2080 6.4438 2085 6.11114 2090 5.82485 2095 5.59301 2100 5.41912