Article: RCA/Jive Label Group CEO Barry Weiss left the company in March 2011 to become the new CEO of Island Def Jam and Universal Republic, which were both part of Universal Music Group. Weiss had been the RCA/Jive Label Group CEO since 2008 and was head of Jive Records since 1991.

Now answer this question: When did Barry Weiss become head of Jive Records?
1991