Year	Percent
1950	17.97768
1955	16.22784
1960	17.03943
1965	17.67323
1970	18.11559
1975	18.09865
1980	17.74902
1985	17.32231
1990	17.20444
1995	16.11064
2000	13.59188
2005	11.15301
2010	10.09839
2015	8.97933
2020	8.42232
2025	7.65094
2030	6.88029
2035	6.24461
2040	5.80892
2045	5.53412
2050	5.33845
2055	5.14764
2060	4.9511
2065	4.78256
2070	4.68111
2075	4.64848
2080	4.65244
2085	4.6549
2090	4.6364
2095	4.60868
2100	4.59559