Year Percent 1950 12.95046 1955 13.53709 1960 13.67246 1965 13.43937 1970 13.36615 1975 13.49568 1980 14.39543 1985 14.20528 1990 14.07136 1995 14.57607 2000 14.88463 2005 13.09426 2010 11.45919 2015 11.09848 2020 10.37767 2025 9.67461 2030 8.89662 2035 8.17678 2040 7.55533 2045 7.02128 2050 6.55455 2055 6.14491 2060 5.79458 2065 5.50508 2070 5.286 2075 5.11955 2080 4.98459 2085 4.87573 2090 4.78996 2095 4.72535 2100 4.68052