Year Percent 1950 18.93457 1955 20.20199 1960 18.70305 1965 18.7139 1970 19.72922 1975 20.05516 1980 21.96668 1985 20.56094 1990 19.86975 1995 21.6283 2000 23.75865 2005 26.12002 2010 27.21009 2015 26.23541 2020 26.66419 2025 28.67085 2030 34.25881 2035 37.09301 2040 36.50528 2045 33.21381 2050 28.58359 2055 26.76567 2060 26.84409 2065 27.44426 2070 27.00379 2075 25.67817 2080 24.87521 2085 24.73004 2090 24.94642 2095 25.19208 2100 25.09991