Second answer first: about 30% of Catholics attend Mass weekly (or more often.) Thus, about 1/3 of a million.
As to "aggressive" Catholics--perhaps you'd like to define that term. "Aggressive" seems to describe Tomas deTorquemada rather well. I don't know of any Catholics up here who are fully "like" TdT, who should be canonized.
By agressive I mean that they are preemptively and actively communicating their convictions to others.