Year   Rate 
2026 $33,800
2025 $32,400
2024 $30,900
2023 $29,100
2022 $27,700
2021 $27,300
2020 $26,400
2019 $25,400
2018 $24,700
2017 $25,400
2016 $25,500
2015 $24,700
2014 $24,500
2013 $23,800
2012 $23,000
2011 $22,300
2010 $22,800
2009 $21,500
2008 $20,100
2007 $18,100
2006 $17,100
2005 $16,400
2004 $15,900
2003 $14,700
2002 $14,700