I just tried in vain to find the Garber page referenced to get the $83 billion figure, but I did find a NASA presentation paper report [] which gives a different 2005 figure, about twice as high: $160 billion.  I did a sanity check by looking up the Consumer price index by country#United States of America, and the curve indicates a rise from ~30 in the 1960's to ~200 in 2005 (indexed to 100 in 1983), a 667% increase. This is consistent with $24 billion x 6.67 = $160 billion, and would have put the $83 billion back in the 1980's. I will try to fix this when I get a chance.     