Not to throw a clod in the churn but how many of those responding were truly converted?
I look at it this way....
If Dr. Graham has 5,000 people profess to be saved at one of his crusades and you have 50 profess to be saved in your church over the period of a year.
Now, suppose we say that only 30% of those in Dr. Graham's crusade were really saved. That would be 1500 people who were genuinely saved.
I would guess your percentage of genuine professions would be about the same: 30%. If so, that means you had 15 people genuinely saved.
Why question the number of people who professed Christ at a Graham crusade when you would probably be very happy to report that you had 50 saved at your church over a year's span...without a disclaimer!