The secret war inside my lower bracket

Is there any trend over the course of the Bush presidency for which this graph would not suffice?

I've been whacking back and forth between Bob Woodward's The War Within: A Secret White House History 2006-2008, and Todd Downs' Bicycle Maintenance and Repair.  Both will make it to my required reading list for the imaginary boy or girl.  I tend to read Bicycle Maintenance, which  I picked up because I had an annoying creak in my bottom bracket, at night in bed so as not to cause nightmares.  The crankarm bolts turned out to be way loose, and I've tightened them now, thank you, hows your mom, but there's still a little creak and I'm wondering if I waited too long to deal with this and whether the bottom bracket now needs an overhaul.  I don't have the tools to do the overhaul, and I can barely read a chapter of Woodward's book every morning without screaming.