Year	Percent of Total
1960-01-01	2.53249251143619
1961-01-01	2.59161852671346
1962-01-01	2.63330728094325
1963-01-01	2.66210094949265
1964-01-01	2.68512966344671
1965-01-01	2.70545599283984
1966-01-01	2.76436729672425
1967-01-01	2.81798094271309
1968-01-01	2.86446538764849
1969-01-01	2.90114171923874
1970-01-01	2.92727186500270
1971-01-01	2.98956171008794
1972-01-01	3.04235497477525
1973-01-01	3.08447572522179
1974-01-01	3.11514888649155
1975-01-01	3.13450270279924
1976-01-01	3.18573155932226
1977-01-01	3.22531677564544
1978-01-01	3.25379458751360
1979-01-01	3.27199224587108
1980-01-01	3.28085929539222
1981-01-01	3.31909415758793
1982-01-01	3.34764592526185
1983-01-01	3.36817862557764
1984-01-01	3.38254612001217
1985-01-01	3.39208019920646
1986-01-01	3.43373095214259
1987-01-01	3.46792368662955
1988-01-01	3.49473334151296
1989-01-01	3.51432207065302
1990-01-01	3.52719974168782
1991-01-01	3.56081619724216
1992-01-01	3.58844028342190
1993-01-01	3.60939266553238
1994-01-01	3.62231892934007
1995-01-01	3.62723906992883
1996-01-01	3.66617406382823
1997-01-01	3.69611559333506
1998-01-01	3.72056200685106
1999-01-01	3.74416984746499
2000-01-01	3.77015439719226
2001-01-01	3.85603674762829
2002-01-01	3.95104407485657
2003-01-01	4.05777843703542
2004-01-01	4.17678393551752
2005-01-01	4.30811480386315
2006-01-01	4.42428164201793
2007-01-01	4.54208258396473
2008-01-01	4.66022651049773
2009-01-01	4.77809385798335
2010-01-01	4.89943118002917
2011-01-01	4.98678109354043
2012-01-01	5.07766657594912
2013-01-01	5.18326579194585
2014-01-01	5.31433531918187
2015-01-01	5.47615702553458
2016-01-01	5.64040615716144
2017-01-01	5.80948000747176