Thru 1999 only 72 permits of the approximate 383,400 issued (less than 0.019% or 19 thousandths of 1%) have been revoked (and not necessarily due to a violent crime or the use of a gun).
In 1979, the Carter Justice Department found that of more than 32,000 attempted rapes, only 32% were actually committed (approximately 10,240). But when a woman was armed with a gun or knife, only 3% of the attempted rapes were actually successful. Almost 11 times less.
In 1966-1967 Orlando was plagued by numerous rapes - the media publicized a safety course teaching women to use a gun. Rapes fell 88% in 1967 while the rate in the rest of the state (and nation) remained the same.
In 1995 law-abiding citizens use guns to defend themselves against criminals as many as 2.5 million times every year -- or about 6,850 times a day.
For those that are interested, the March/April issue of American Handgunner conatins an article by Massad Ayoob referring to a watchmaker named Thomas. Mr. Thomas was attacked on 4 separate occasions, by a total of 11 assailants - one incident involved 5 attackers. Mr. Thomas saved his own life in each instance, receiving multiple gunshot wounds, but managed to kill 4 of the 11, the rest fleeing for their lives.