Year % of total labor force 1991 30.38414165519439 1992 30.8037532309404 1993 31.250920198179344 1994 31.708108063691004 1995 32.773893134549205 1996 32.829429511368375 1997 33.81471834085693 1998 33.733707634692564 1999 33.5068618369845 2000 33.886649826486234 2001 33.68430200465106 2002 34.01520828107905 2003 34.37647034733694 2004 35.01745857631848 2005 35.47577535081782 2006 36.027581080072196 2007 36.308829906891184 2008 36.32756335566213 2009 36.79384424135229 2010 36.767156657173174 2011 37.02976910517317 2012 37.480681438061445 2013 37.565438561591854 2014 37.07417175683023 2015 37.3549666820246 2016 37.45607140246971 2017 37.256113225865796 2018 37.53872432080536 2019 38.331203309197754 2020 38.012477421483446 2021 38.34177170903611 2022 38.907588676754855 2023 39.45317700758988