Year	Percent
1950	31.35602
1955	30.58088
1960	22.56041
1965	20.0268
1970	17.7477
1975	20.65379
1980	23.17238
1985	26.44611
1990	29.12098
1995	30.59183
2000	31.11282
2005	32.57797
2010	31.26683
2015	32.60148
2020	33.0456
2025	31.90671
2030	29.9169
2035	26.69682
2040	24.07822
2045	22.64447
2050	22.11121
2055	21.44412
2060	20.62178
2065	19.8679
2070	19.32772
2075	19.09896
2080	19.15959
2085	19.33142
2090	19.44076
2095	19.45799
2100	19.43559