Year Percent 1950 13.53734 1955 13.62118 1960 13.72676 1965 14.57755 1970 15.01315 1975 14.75119 1980 13.98475 1985 15.02726 1990 15.3897 1995 13.41107 2000 12.67567 2005 10.63168 2010 7.91636 2015 7.19747 2020 7.48517 2025 7.14733 2030 6.39487 2035 5.55877 2040 5.04953 2045 4.91413 2050 4.95081 2055 4.91692 2060 4.71686 2065 4.43877 2070 4.2312 2075 4.18071 2080 4.25105 2085 4.34117 2090 4.36126 2095 4.30845 2100 4.24965