Year % 1990 25.925658619943412 1991 26.143169916124904 1992 26.834461042056613 1993 27.0194793558692 1994 27.164425500203503 1995 27.26243946690906 1996 27.347432217093644 1997 27.284982953328672 1998 27.366820395951017 1999 27.272846904826785 2000 27.650573930331568 2001 28.35412645986954 2002 28.240330749385738 2003 28.235536180918984 2004 28.097306656428373 2005 27.967838537703162 2006 27.731455080179142 2007 27.651446831497406 2008 27.505052128784424 2009 27.44366253827461 2010 26.895709893134725 2011 26.834760813051354 2012 26.748255029985053 2013 26.68569671655557 2014 26.662456396165307 2015 26.579806111458918 2016 26.610425527408744 2017 26.583698244136652 2018 26.57283117727617 2019 26.599432675235686 2020 26.604362833581476 2021 26.62523870440317