According to the Association Roster for the last quarter there were just under 900 licensees working in the Corpus Christi Area. Finding an # of transactions in difficult in any area because you have part time licensees and full timers. What you should know is in most markets 10% of the agents sale around 90% of the transactions. The average agent sales3-6 transactions a year.
The best numbers I can see are over 1000 Realtors in the Association. The number of sales you can get from http://recenter.tamu.edu/data/hs/hs190b.htm . Not sure average transactions is a good reference though. There are agents who do one or two a year and others who probably do a 100 or more. The average in CC might be 3 or 4 per agent, but obviously there's a big difference there.