Year Percent 1950 27.58793 1955 25.26184 1960 25.64495 1965 24.64284 1970 24.63109 1975 25.54443 1980 26.66885 1985 27.70431 1990 29.43916 1995 30.6339 2000 28.98057 2005 27.16265 2010 25.38634 2015 25.33052 2020 24.66127 2025 23.04622 2030 21.43001 2035 20.13373 2040 20.01308 2045 20.30954 2050 20.65256 2055 20.73145 2060 20.46234 2065 20.14932 2070 20.04302 2075 20.21753 2080 20.50131 2085 20.66127 2090 20.57153 2095 20.30026 2100 20.022