There fixed for you. Since we know there are not more than 6 million that actually show up once in a while, the numbers from PR dept. are somewhat misleading.
Well, I was actually basing it upon the Pew study released just this month...
But you are right about one thing: People don't always respond truthfully to polls...so I should have qualified it as around 80% of Mormons say they tithe...Perhaps around 80% have tithed at some point in their lives...How many of them actually do...well...I don't know.