Year	Percent
1950	13.35659
1955	13.81896
1960	13.79669
1965	14.05773
1970	14.3542
1975	14.20704
1980	14.1623
1985	13.5598
1990	14.41935
1995	14.13925
2000	13.22567
2005	11.09894
2010	9.75892
2015	8.7616
2020	8.0907
2025	8.15466
2030	7.41976
2035	6.54058
2040	5.94233
2045	5.64986
2050	5.59875
2055	5.59568
2060	5.46971
2065	5.2291
2070	4.98311
2075	4.84468
2080	4.82907
2085	4.86251
2090	4.86033
2095	4.79621
2100	4.70447