I don't know how well stats are kept on this, but here a local news outlet (Albany, NY) reporting on debate over location of gun show in town. Contains a list of media reported (likely even more than this) discharges at gun shows from late 2012 through early 2014:
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Negligent Gun discharge death
June 2014 – Cedar Park, Texas – a man was fatally shot by his son-in-law after he negligently discharged a gun he was holding in the parking lot outside of a gun show
Negligent Gun discharges at 10 gun shows have resulted in injuries to 17 persons
December 2012 – Mount Clemens, Michigan – a man shot himself in the leg while emptying his gun in a gun clearance area at the entrance of a gun show
January 6, 2013- Marietta, Ohio – a man shot another man in the ankle at a gun show
January 19, 2013 – the first annual “Gun Appreciation Day” – 5 people were shot at 3 different gun shows: (1) Raleigh, NC – 3 people were injured when a man’s 12 gauge shot gun discharged at the check-in booth; (2) Medina, Ohio – one man was shot by his partner when his gun discharged when he was checking in (like the incident this past weekend in Bloomsburng, PA, the gun’s magazine had been removed, but one round remained in the chamber); and (3) Indianapolis, Indiana – a man shot himself as he was leaving a gun show in Indianapolis, Indiana.
January 25, 2013 – Des Moines, Iowa – a vendor shot himself in the hand at a gun show as he was setting up his display
February 2013 – Trotwood, Indiana – A man shot himself in the hand in a the parking lot of Hara Arena after purchasing a gun at the gun show
April 2013 – Boise, Idaho – Five persons were injured by shrapnel when a large-caliber handgun was discharged
July 2013 – Hot Springs, Arkansas – two persons were injured when a pistol was discharged
June 2014 – Bloomington, Pennsylvania – a vendor shot a woman in the leg while showing her how to use a gun and holster
Negligent Gun discharges at 8 guns shows not resulting in any injuries
January 2013 (2 shows) – Monroe, Washington and LaPorte, Indiana
March 2013 (3 shows) – Lewisville, Texas, Chelalis, Washington and Colorado Springs, Colorado
April 2013 – Hastings, Minnesota
November 2013 – Myrtle Beach, South Carolina
February 2014 – Muscle Shoals, Alabama
http://blog.timesunion.com/lawrencewhite/gun-show-liabilities/1958/