Year Percent 1950 12.1844 1955 11.28098 1960 13.30909 1965 13.01459 1970 12.7623 1975 12.90233 1980 13.12512 1985 13.45585 1990 13.60354 1995 13.63283 2000 13.39193 2005 13.16384 2010 11.93352 2015 10.43027 2020 8.72071 2025 8.27571 2030 7.80403 2035 7.18831 2040 6.47242 2045 5.88165 2050 5.50689 2055 5.23686 2060 5.00541 2065 4.78501 2070 4.59412 2075 4.45727 2080 4.37682 2085 4.34742 2090 4.33957 2095 4.33422 2100 4.32527