Year Percent 1950 28.93067 1955 28.05805 1960 27.69498 1965 27.07414 1970 27.02475 1975 27.25427 1980 27.72928 1985 28.08489 1990 27.98395 1995 27.61601 2000 26.39741 2005 25.49774 2010 25.47429 2015 26.23088 2020 27.19429 2025 27.94941 2030 28.63714 2035 29.20867 2040 29.75453 2045 30.37186 2050 30.84556 2055 31.20197 2060 31.32579 2065 31.35165 2070 31.32377 2075 31.23354 2080 31.07593 2085 30.83213 2090 30.51893 2095 30.17646 2100 29.82128