Year Percent 1950 28.39214 1955 28.85461 1960 28.64031 1965 27.80152 1970 26.742 1975 25.22158 1980 24.10178 1985 26.01719 1990 28.06214 1995 30.36694 2000 31.94354 2005 32.78639 2010 33.03207 2015 33.59889 2020 33.73677 2025 33.51234 2030 32.71832 2035 31.57599 2040 30.14637 2045 28.56805 2050 27.22373 2055 25.94995 2060 24.68011 2065 23.55382 2070 22.62738 2075 21.92046 2080 21.40434 2085 21.00744 2090 20.71538 2095 20.51537 2100 20.38975