Year	Percent
1950	29.0729
1955	28.26855
1960	28.19327
1965	28.04204
1970	29.05977
1975	29.11988
1980	29.17036
1985	29.84994
1990	30.08599
1995	30.15739
2000	28.5705
2005	27.23429
2010	26.03327
2015	26.30261
2020	25.57354
2025	23.91009
2030	22.58961
2035	21.87988
2040	21.92384
2045	22.19411
2050	22.34101
2055	22.15493
2060	21.71495
2065	21.37296
2070	21.2364
2075	21.27915
2080	21.35453
2085	21.29037
2090	21.02849
2095	20.66536
2100	20.32734