Year % of total labor force 1991 29.169908810073476 1992 29.31200362288374 1993 29.301950634452023 1994 29.578472183613435 1995 29.61400713651736 1996 29.71558059738593 1997 29.80219749290513 1998 29.97131135472887 1999 30.046080103211096 2000 30.062293707114993 2001 30.091144945721414 2002 30.091673506259184 2003 30.25233053765492 2004 30.34817983743051 2005 30.530007298004495 2006 30.521683201502388 2007 30.688624898866173 2008 30.609505832740343 2009 30.664953013004556 2010 30.616038125075452 2011 30.52211594348062 2012 30.48862133592072 2013 30.533555289700377 2014 30.619548124560637 2015 30.819767689513252 2016 30.980192949153267 2017 31.113836684835146 2018 31.191343340677847 2019 31.341355586920454 2020 31.099402236876045 2021 31.45934694445372 2022 31.646988116626737 2023 32.77875240303725