First of all, your numbers don't even match what's found on bea.gov. here are the actual
Reagan: 2.4t (300b per year avg)
Bush: 4.0t (500b per year avg)
Obama: 1.8t (450b per year avg)
Hopefully, if nothing else, this little exercise will teach you why playing with nominal figures is completely meaningless.
That is, unless you believe that Obama is doing a better job with the economy than Reagan did?