It's interesting to see a comparison like that, but it's important to remember that as events come up, those projections can change a lot. Just as an example, Bill Clinton's long-term budgeting was calculated to be well into deficit spending for his entire 8 years, and yet we ended up with a "paper surplus." The difference, which he hadn't planned on, was a big boom in the economy and major restructuring after 1994.
The CBO projected George Bush's budgets to be in surplus for his entire 8 years, and yet it has been in deficit since the first year. What happened? A minor recession the last year of Clinton, plus 9/11, plus a couple of wars.
You could go back farther, say to 1935, and see what projections were and how far they were off, but it would just prove the point that most projections are pretty unreliable.
An example of how hard it is to predict the cost of any program would be Medicare, which was supposed to be a fairly small program and now is threatening to break the whole US budget.