Year Percent 1950 16.26385 1955 17.02355 1960 16.35934 1965 16.6863 1970 20.49323 1975 22.13169 1980 25.8096 1985 24.2732 1990 23.09753 1995 24.73269 2000 26.27609 2005 29.33031 2010 29.11277 2015 28.03598 2020 27.20037 2025 27.82837 2030 30.85736 2035 30.66564 2040 28.22356 2045 25.35747 2050 22.90423 2055 23.91581 2060 26.22903 2065 27.48465 2070 27.24501 2075 25.58685 2080 24.50584 2085 24.3846 2090 25.03795 2095 25.6917 2100 25.68759