Year	% of total
1990	26.16240533947599
1991	26.718895188537424
1992	27.121629084455748
1993	27.44349833225583
1994	26.965026838885723
1995	27.058142671386495
1996	27.015948582864578
1997	27.011580590392096
1998	26.506919508220957
1999	26.68665781056101
2000	26.699257987169595
2001	27.63626595300256
2002	27.411135826606923
2003	27.301411373623864
2004	26.689447813088908
2005	26.326260044365906
2006	27.119991281436917
2007	27.14843131450306
2008	27.351035956702873