Year	Percent
1950	5.9493
1955	6.71301
1960	7.20826
1965	7.71054
1970	7.14864
1975	5.22413
1980	4.71441
1985	4.94348
1990	5.18129
1995	4.74736
2000	4.5618
2005	4.19436
2010	3.99761
2015	4.1232
2020	4.28825
2025	4.36487
2030	4.26765
2035	4.10667
2040	4.00779
2045	4.02353
2050	4.14878
2055	4.29157
2060	4.36699
2065	4.35344
2070	4.29952
2075	4.26746
2080	4.29961
2085	4.358
2090	4.40202
2095	4.39563
2100	4.34362