Year	Percent
1950	28.25818
1955	27.42809
1960	25.67557
1965	26.1218
1970	26.25149
1975	28.53865
1980	31.7927
1985	34.4118
1990	33.28309
1995	30.55504
2000	25.59042
2005	23.96004
2010	22.8839
2015	22.87761
2020	22.72624
2025	22.48981
2030	22.07813
2035	21.63826
2040	21.52898
2045	21.5262
2050	21.83185
2055	21.81501
2060	21.58254
2065	21.36466
2070	21.20962
2075	21.10939
2080	21.00434
2085	20.85152
2090	20.64891
2095	20.45063
2100	20.30185