Year	Percent
1950	29.49077
1955	27.94478
1960	26.16248
1965	27.41748
1970	29.95163
1975	33.0262
1980	34.49977
1985	37.18036
1990	35.35071
1995	34.50919
2000	31.12784
2005	28.16563
2010	24.3515
2015	23.45731
2020	23.54865
2025	24.2569
2030	25.32882
2035	23.9029
2040	22.44987
2045	21.7524
2050	21.71424
2055	22.59048
2060	23.01733
2065	22.77389
2070	22.07039
2075	21.46356
2080	21.29891
2085	21.50743
2090	21.72973
2095	21.67782
2100	21.36309