2009?!?
I think it's time for some new shoes. Almost ten years can be a long time for the life of a tire. Generally speaking, six to ten years is getting a bit old and should be inspected at pretty regular intervals. Let's put it this way, think about a blowout at highway speeds in heavy traffic, (worst case scenario). And while those may appear to be surface or superficial cracks, you are only getting further and further away from its production date. If you need to, you might wait till October for Discount Tire Direct's eBay sale. $100 off for every $400 spent. Depending on selection, you could save $200 on a set of four tires.
https://tires.tirerack.com/tires/How Old Is Too Old