Year	% of total
1992	36.43591659687757
1993	38.83457118049272
1994	40.04347161914052
1995	39.72320318738898
1996	39.48474969821878
1997	40.38719603674692
1998	43.151462327043
1999	43.38272883222206
2000	42.44024902139806
2001	41.574953048512015
2002	45.68873765420886
2003	50.390730008438
2004	49.63291084137435
2005	48.91264247966506
2006	48.58020188660127
2007	48.50289957557467
2008	48.96287000024372
2009	45.88310639779502
2010	45.95535799959021
2011	49.79966005086561
2012	51.68088954042791
2013	46.196751926639294
2014	46.3271555856978
2015	46.078627806200075
2016	40.757720573885834