Because it’s not adjusted for inflation, nominal GDP outstrips real GDP when prices are rising
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
2016
2018
2020
0
5
10
15
$20 trillion
Real GDP
Nominal GDP