You might mean, the
size of increase fell. Tax revenues have not fallen. Big difference (
source)
FY 2020 - $3.64 trillion, budgeted.
FY 2019 - $3.44 trillion, estimated.
FY 2018 - $3.33 trillion.
FY 2017 - $3.32 trillion.
FY 2016 - $3.27 trillion.
FY 2015 - $3.25 trillion.
FY 2014 - $3.02 trillion.
FY 2013 - $2.77 trillion.
FY 2012 - $2.45 trillion.
FY 2011 - $2.30 trillion.
FY 2010 - $2.16 trillion.
FY 2009 - $2.10 trillion.
FY 2008 - $2.52 trillion.
FY 2007 - $2.57 trillion.
FY 2006 - $2.4 trillion.
FY 2005 - $2.15 trillion.
FY 2004 - $1.88 trillion.
FY 2003 - $1.72 trillion.
FY 2002 - $1.85 trillion.
FY 2001 - $1.99 trillion.
FY 2000 - $2.03 trillion.