Year Percent 1950 27.80808 1955 28.07276 1960 27.34098 1965 26.38186 1970 26.29074 1975 27.1543 1980 28.65414 1985 30.85385 1990 32.08969 1995 32.31639 2000 32.32066 2005 31.83417 2010 31.90964 2015 32.05407 2020 31.6924 2025 31.14431 2030 30.3717 2035 29.82033 2040 29.35581 2045 28.77768 2050 28.06452 2055 27.25356 2060 26.44766 2065 25.69856 2070 24.99327 2075 24.357 2080 23.78558 2085 23.27894 2090 22.85311 2095 22.50066 2100 22.21201