Year Percent 1950 15.03312 1955 15.83267 1960 15.60574 1965 15.94593 1970 15.92616 1975 15.0477 1980 14.30308 1985 12.83119 1990 12.80704 1995 11.40915 2000 10.60335 2005 9.64243 2010 8.56002 2015 8.29738 2020 7.56131 2025 7.04677 2030 6.51902 2035 6.08196 2040 5.74174 2045 5.51183 2050 5.31677 2055 5.12283 2060 4.94778 2065 4.78238 2070 4.66342 2075 4.58691 2080 4.53495 2085 4.48171 2090 4.42622 2095 4.3809 2100 4.34971