Pastoral Math is what we call it when a pastor "rounds up" their average attendance to the nearest thousand. They have 153 people attending so they make it "almost" 200.
But the truth is, we are bad when it comes to using and abusing statistical information. Christianity Today has a great article about Evangelicals misusing statistics and misrepresenting what is actually going on in the world. Check it out here.
Thanks to Church Marketing Sucks for the tip.