I fish almost entirely strip pits here in southern Indiana.  Based on the survey data that the DNR makes available online, I seem to catch fish at about the same ratio that populates these lakes.  

For example, about 10-15% keeper size (>14 inches), 2-3 % good fish (>2 lbs) and ~ .5% over 5 lbs.  The rest are < 14 inches.

My question is, is this a typical ratio for most of you (adjusted to the size of bass in your waters), or can I focus more intently on keeper fish.  If so, how?

Cephkiller,

You have already proven that there are bigger fish in the water you are fishing. Fish for 'em! Larger lures, deeper water and a slower presentation are the keys. You may not catch quite as many fish, but you'll still catch lots of fish and your percentage of 5+ pounders will improve dramatically.

When you're fishing topwater, fish the full sized Spook or Sammy. Use big worms, I like 6" Senkos. Try the Yamamoto Fat Ika, it's my #1 big bass lure right now. Just fish for big bass and I think you will be surprised how successful you can be.

Go with the swim baits, man.  Big, natural looking trout, or forage fish patterns.  Alot of big bass have been caught and recorded on swim baits.  A.C. Plugs, Titan Swim Baits, etc.  Look into 'em.    

As these guys have said, large baits. Use large plastic worms. around 9". also a bass jig is one of the best big bass producers. buzzbaits too.

The rest has been said, my advice: if you 're going to hunt for the BIGUNS get ready mentally and physically to cast hour after hour without getting any strikes, you 're targeting the smallest population, not only there are few of them, they didn 't get big by being dumb.

Yup.  For sure.  Listem to Raul.  For, that's gonna be the toughest part of your quest for that big bass.