This graph is a bit simplified. Reagan, Clinton and Bush II served 8 years, Bush I only 4, and Obama has only served 2 1/2.
And debt can arise from additional spending, or decreased revenue, or both.
If you "annualize the increase in debt, Obama would be just a tad below Bush II (Bush II - 10.75%, Obama 9.2%)
But Bush choose to reduce revenue and increase spending; Obama was stuck with both Bush's decreased revenue from his tax cuts and the even further reduced revenue from Bush's Recession. And a big chunk of Obama's increased spending was the "one time only" stimulus package.
Of course, Obama has embraced many GOP economic practices, so we'll have to see how this plays out over time.
So far, though, the Republican Presidents are way ahead when it comes to fiscal irresponsibility.