Also from what I read they came from all over the world so they were already diagnosed to be possessed. I remember in the books that he did it all day long because of the horrible need of the victims.
Whatever it is worth but wikipedia has this in the numbers.
In October, 2000, he said he had performed over 50,000 exorcisms (which ranged from "a few minutes" to "several hours" in length[3]) meaning he averaged close to ten exorcisms per day during his career up to the year 2000. In March 2010, he claimed that number had increased to 70,000.[4] The math for this claim plays out as such: 70,000 exorcisms/(365days*24yrs) = roughly 8 exorcisms per day on average from 1986-2010, which is a conceivable answer............
Fr. Amorth offers the following guidelines to those exercising the charism of exorcism. Any such person must be highly regarded for his prayer life, faith, acts of charity and judgment. In addition he must rely solely on the Word of God and traditional prayer, be completely detached from monetary concerns, profoundly humble and treasure obscurity.[7] "Heal the sick, raise the dead, cleanse those who have leprosy, drive out demons. Freely you have received, freely give." Matthew 10:8
http://en.wikipedia.org/wiki/Gabriele_Amorth
Thanks for #55