To answer the questions about "how many of the delays are due to NON-weather related reasons?" or "What is the average number of minutes of delay?"........take a look at the federal government data base at:

www.transtats.bts.gov


It let's you look at 2 categories of non-weather delays
"Carrier delay" crew, etc
"Late inbound aircraft"
as well as providing info on "number of minutes" late

You can look-up these data by airline or by airport or by your favorite city pair..... and choose the range of months that makes sense to you.

Make your own individualized reports...... for me, an airline with the lowest cancellation rate out of OKC is better than one with a low delay rate!