easy answer! one reason is could be that the Catholic Church believes in real Demon possession. If one doesn't believe in Demon possession, he/she is highly unlike to report one! He/she would attribute the experience to another cause. Second possible reason: the devil spends more energy attacking Catholics!
Howantstono--I am deeply offended by your statement. With all of the non-christian hate that christians receive, it is sad that you will not focus your energy elsewhere. Your interpretation of that passage in revelation is not only incorrect, but sadly misguided.
The Catholic Church holds the same beliefs as the 1st century christians, who by the way were using the name 'Catholic' by the end of the 1st cent AD because Jesus founded the catholic church. Your Christian denomination is only about 500 years. Mine is over 2000 years old. You can blindly follow what your preacher has decided her interprets scripture to be. I will gladly listen to the Catholic church who had stood since the time of Christ.