Year Percent 1990 1.92 1991 1.92 1992 2.25 1993 1.98 1994 2.35 1995 2.28 1996 2.4 1997 1.96 1998 1.47 1999 3.4 2000 2.21 2001 2.26 2002 2.02 2003 2.43 2004 2.38 2005 3.44 2006 2.75 2007 3.03 2008 2.91 2009 3.07 2010 3.19 2011 3.39 2012 4 2013 3.64 2014 3.78 2015 4.17 2016 3.65 2017 3.774 2018 3.899 2019 4.023 2020 4.147 2021 4.272 2022 4.396 2023 4.52 2024 4.645 2025 4.769 2026 4.893 2027 5.018 2028 5.142 2029 5.266 2030 5.391