Year % 1997 11.249590029517877 1998 12.885906040268459 1999 11.760925449871461 2000 12.618724559023061 2001 11.753118844386073 2002 13.996316758747689 2003 15.377957299480663 2004 16.023054755043223 2005 17.448891448315575 2006 17.642045454545453 2007 18.643586833144152 2008 18.622448979591837 2009 19.277448489980237 2010 19.56772334293949 2011 19.50534007869589 2012 21.191680719505335 2013 21.783328492593668 2014 23.93138357705287 2015 24.20036210018106 2016 25.537859737356808 2017 26.45218945487042 2018 27.736625514403304 2019 28.293084522502753 2020 29.466817923993204 2021 31.4342403628118 2022 32.86899822169532 2023 33.116306599585684