Year	Percent
1950	4.191
1955	3.8459
1960	3.73219
1965	3.69493
1970	3.71493
1975	3.75636
1980	3.80892
1985	3.85774
1990	4.12273
1995	4.16624
2000	4.19132
2005	4.23538
2010	4.27726
2015	4.27707
2020	4.33409
2025	4.46084
2030	4.64953
2035	4.88943
2040	5.19318
2045	5.58261
2050	6.05864
2055	6.63462
2060	7.31848
2065	8.20991
2070	9.33681
2075	10.64197
2080	12.02345
2085	13.46355
2090	14.97813
2095	16.5595
2100	18.18247