Year	Percent
1990-01-01	52.346700000000000
1991-01-01	51.100500000000000
1992-01-01	44.719400000000000
1993-01-01	38.925100000000000
1994-01-01	40.108700000000000
1995-01-01	38.293400000000000
1996-01-01	37.173100000000000
1997-01-01	32.724000000000004
1998-01-01	28.384400000000000
1999-01-01	25.483900000000000
2000-01-01	22.243200000000000
2001-01-01	18.441400000000000
2002-01-01	17.214800000000000
2003-01-01	20.217400000000000
2004-01-01	21.956000000000000
2005-01-01	19.730800000000000
2006-01-01	17.592900000000000
2007-01-01	18.011000000000000
2008-01-01	21.661400000000000
2009-01-01	24.706300000000000
2010-01-01	28.398700000000000
2011-01-01	29.411700000000000