How many trillion dollars higher was the US GDP in 1990 than the National Debt in 2001?
return the  US GDP ;return #1 in  1990 ;return the  National Debt ;return #2 in  2001 ;return difference of #2 and  #4 ;return division of #5 and  one trillion
['select', 'filter', 'select', 'filter', 'arithmetic', 'project']