Year % 1998 12.151324965132506 1999 12.175019695776022 2000 12.11462798755065 2001 12.372188139059304 2002 13.737908797789038 2003 13.651877133105808 2004 14.357591161367298 2005 14.582496989160976 2006 15.137912115317473 2007 16.226584296532476 2008 17.171023591152093 2009 18.13574049044217 2010 18.07912320338413 2011 18.580276322058122 2012 19.903189066059223 2013 20.839506172839513 2014 21.601302494852277 2015 21.917741779028038 2016 22.33845584151084 2017 22.413953922208744 2018 23.01208204551841 2019 23.39398952302178 2020 24.389676819344345 2021 24.64870921058774 2022 25.203097534324666 2023 25.47865211564235