Annual % of total
1960 -0.018782870022539443
1961 -0.017985611510791366
1962 -0.01518141794443601
1963 -0.012599218848431397
1964 -0.01301913813305559
1965 0
1966 -0.01163061177017911
1967 0.01126126126126126
1968 0.06106870229007633
1969 0.06737895851381268
1970 0.20930020930020926
1971 0.48085329603077465
1972 0.5973205904940695
1973 0.7530120481927711
1974 1.7768741159830268
1975 3.029450384543238
1976 3.0615942028985503
1977 3.4451981435201713
1978 3.6827933640232775
1979 4.355016538037487
1980 4.8937132519222075
1981 5.510993677455883
1982 6.176794473921314
1983 6.204813764070651
1984 7.0766638584667225
1985 7.292146211214439
1986 7.031385469048032
1987 7.916552792201877
1988 7.881462799495587
1989 8.845117532286537
1990 8.623754904223402
1991 9.185566017079044
1992 9.65295623632385
1993 10.650757192174913
1994 10.710842920873445
1995 11.573335635359117
1996 12.364980686207682
1997 12.291955555555555
1998 12.223333333333333
1999 12.582923871547273
2000 12.751864561885151
2001 12.84586802480071
2002 13.070578379619002
2003 13.420042372881355
2004 13.71075750883392
2005 13.900209378407851
2006 13.626275285839927
2007 13.862843362425355
2008 14.297711298932384
2009 14.132267002518892
2010 15.248750276487502
2011 14.840711337703327
2012 15.783555450906523
2013 16.23499310027599
2014 15.39530833123584
2015 16.73309505508583
2016 17.3305326937642