The British Journal of Urology Int has an update on the epidemiology of
zipper-related genital injuries:
Between 2002 and 2010, an estimated 17,616 patients presented to US EDs
with trouser zip injuries to the genitals. The penis was almost always
the only genital organ involved. Zip injuries represented nearly
one-fifth of all penile injuries. Amongst adults, zips were the most
frequent cause of penile injuries. Annual zip-related genital injury
incidence remained stable over the study period.
(Via
Marginal Revolution.)