Year	Percent
1950	21.79621
1955	22.12885
1960	21.84037
1965	21.76287
1970	21.30958
1975	21.13792
1980	21.50493
1985	22.08166
1990	24.36268
1995	25.96573
2000	27.66135
2005	29.18982
2010	29.27674
2015	28.69771
2020	27.21276
2025	25.40014
2030	24.08913
2035	23.75463
2040	24.11695
2045	24.52732
2050	24.2238
2055	23.6195
2060	23.30141
2065	22.98421
2070	23.02625
2075	23.18822
2080	23.11482
2085	22.82186
2090	22.49298
2095	22.28234
2100	22.22252