Biased Numbers

During last night's Republican presidential debate on Bloomberg Television, a screen shot, right before a commercial, informed us that the national debt has increased $4 trillion under President Obama, but that it had gone up $5 trillion under President George W. Bush.  I'm not about to defend W for starting what would become a decade of out-of-control spending, but a little math does shed some light on this factoid.  It has taken Obama only a third of the time (34 months) to effectively achieve what Bush did in 96 months.