Year Percent 1950 21.4541 1955 22.16046 1960 22.05722 1965 22.22271 1970 22.78829 1975 23.14656 1980 22.9988 1985 22.16787 1990 21.27601 1995 20.77941 2000 21.37248 2005 22.4767 2010 23.00669 2015 23.84007 2020 24.48225 2025 24.52385 2030 25.2101 2035 25.79356 2040 25.99948 2045 26.40417 2050 26.28643 2055 25.67143 2060 25.20284 2065 24.93383 2070 24.72113 2075 24.50713 2080 24.22375 2085 23.9178 2090 23.64733 2095 23.4389 2100 23.28048