Year Percent 1990 2.561 1991 2.669 1992 2.789 1993 2.94 1994 2.969 1995 2.991 1996 2.97 1997 2.663 1998 2.388 1999 2.14 2000 2.594 2001 3.142 2002 3.8 2003 3.71 2004 1.8 2005 3.17 2006 1.96 2007 2.14 2008 1.94 2009 2.08 2010 2.11 2011 1.98 2012 2.15 2013 1.89 2014 1.15 2015 2.3 2016 2.15 2017 2.081 2018 2.011 2019 1.942 2020 1.872 2021 1.803 2022 1.733 2023 1.664 2024 1.594 2025 1.525 2026 1.455 2027 1.386 2028 1.317 2029 1.247 2030 1.178