Year Percent 1950 13.65412 1955 12.67908 1960 9.58759 1965 9.56639 1970 11.95926 1975 12.68688 1980 12.76699 1985 12.19751 1990 12.0982 1995 14.31152 2000 14.87496 2005 12.05196 2010 8.48013 2015 6.54297 2020 6.76038 2025 7.56716 2030 7.16617 2035 6.15613 2040 5.12523 2045 4.60293 2050 4.62377 2055 4.8186 2060 4.80192 2065 4.52175 2070 4.20512 2075 4.06898 2080 4.17287 2085 4.37321 2090 4.49051 2095 4.44166 2100 4.30922