Year Percent 1950 11.77943 1955 10.80859 1960 11.92049 1965 11.83802 1970 11.41802 1975 9.75135 1980 9.15534 1985 8.35174 1990 8.73965 1995 7.80833 2000 7.10297 2005 6.62034 2010 6.31522 2015 6.2772 2020 5.88039 2025 5.53009 2030 5.2822 2035 5.11395 2040 4.99242 2045 4.91921 2050 4.84403 2055 4.75371 2060 4.66818 2065 4.61138 2070 4.59043 2075 4.59013 2080 4.59082 2085 4.58447 2090 4.57283 2095 4.56515 2100 4.56581