Year	Percent
1950	15.62631
1955	15.20624
1960	14.38918
1965	14.86694
1970	15.18187
1975	16.18113
1980	17.48008
1985	18.07847
1990	19.42111
1995	20.90154
2000	24.18497
2005	27.76427
2010	31.03505
2015	32.71536
2020	31.56904
2025	30.15258
2030	27.5963
2035	26.10822
2040	25.156
2045	23.30965
2050	22.31118
2055	20.66386
2060	19.65926
2065	19.91675
2070	20.62698
2075	21.23063
2080	21.26408
2085	20.90512
2090	20.3581
2095	20.07293
2100	20.27699