Year	Percent
1950	31.9404
1955	31.78188
1960	32.34558
1965	30.08451
1970	29.24806
1975	28.50307
1980	28.4011
1985	28.52079
1990	27.34787
1995	27.18188
2000	27.99803
2005	28.21977
2010	28.14371
2015	26.54031
2020	23.73432
2025	21.8497
2030	20.49375
2035	20.27482
2040	21.39173
2045	22.05479
2050	21.5764
2055	21.11412
2060	20.88882
2065	21.0871
2070	21.62535
2075	22.16015
2080	22.25381
2085	21.90527
2090	21.47883
2095	21.26775
2100	21.32482