Year	Percent of Total
1960-01-01	2.98176619892782
1961-01-01	3.03800457997598
1962-01-01	3.07907295847869
1963-01-01	3.11192892361550
1964-01-01	3.14644967916184
1965-01-01	3.18661605094481
1966-01-01	3.24741161756326
1967-01-01	3.30969513811399
1968-01-01	3.36842308870311
1969-01-01	3.41549064511174
1970-01-01	3.44741077629461
1971-01-01	3.47525000920647
1972-01-01	3.49112845322639
1973-01-01	3.49472833420288
1974-01-01	3.48466586943626
1975-01-01	3.46101130225867
1976-01-01	3.43182934654985
1977-01-01	3.39334539072512
1978-01-01	3.35211431171973
1979-01-01	3.31499512340440
1980-01-01	3.28655358854641
1981-01-01	3.28182085835230
1982-01-01	3.28222378858684
1983-01-01	3.29276509810111
1984-01-01	3.32055517817041
1985-01-01	3.37001077676478
1986-01-01	3.45125626874815
1987-01-01	3.54886502827545
1988-01-01	3.66110337194754
1989-01-01	3.78545829316842
1990-01-01	3.92028485233571
1991-01-01	4.07926601171053
1992-01-01	4.23806003638254
1993-01-01	4.39428927016711
1994-01-01	4.54567749681179
1995-01-01	4.69130975498197
1996-01-01	4.82044403759087
1997-01-01	4.94136020968378
1998-01-01	5.05483125392654
1999-01-01	5.16039426265618
2000-01-01	5.25891830606717
2001-01-01	5.36704823741018
2002-01-01	5.46613202979849
2003-01-01	5.55999029216554
2004-01-01	5.65342419477466
2005-01-01	5.75007363765425
2006-01-01	5.83294184463772
2007-01-01	5.92141819793651
2008-01-01	6.00892082455675
2009-01-01	6.08317682298258
2010-01-01	6.14003136536016
2011-01-01	6.17294173927045
2012-01-01	6.18881639887983
2013-01-01	6.21140088199863
2014-01-01	6.27422301747516
2015-01-01	6.39615666573438
2016-01-01	6.55592887628709
2017-01-01	6.76914222271219