Year Percent 1950 17.21136 1955 16.8503 1960 17.36935 1965 17.8522 1970 18.0102 1975 17.85809 1980 17.00805 1985 16.26066 1990 14.97796 1995 13.39822 2000 12.10462 2005 10.4579 2010 9.60641 2015 8.39075 2020 7.77314 2025 7.02134 2030 6.1283 2035 5.5442 2040 5.28635 2045 5.25726 2050 5.26598 2055 5.15168 2060 4.92759 2065 4.70203 2070 4.5812 2075 4.57753 2080 4.6193 2085 4.62488 2090 4.57011 2095 4.48788 2100 4.43194