Year Percent 1950 12.90463 1955 13.37656 1960 13.78794 1965 14.29019 1970 14.46237 1975 14.4444 1980 13.18532 1985 11.46465 1990 9.77804 1995 8.72201 2000 7.82657 2005 6.80893 2010 6.00954 2015 5.693 2020 5.23902 2025 4.61726 2030 4.31915 2035 4.26484 2040 4.22059 2045 4.13325 2050 4.05892 2055 4.00159 2060 3.98275 2065 4.02798 2070 4.11558 2075 4.18182 2080 4.21567 2085 4.22584 2090 4.24717 2095 4.28884 2100 4.34711