Background: Richard John Santorum (born May 10, 1958) is an American attorney, author, politician, and CNN Senior Political Commentator. A member of the Republican Party, he served as a United States Senator from Pennsylvania from 1995 to 2007 and was the Senate's third-ranking Republican from 2001 to 2007. He ran as a candidate for the 2012 Republican Party presidential nomination, finishing second to Mitt Romney. Santorum was elected as a United States Senator from Pennsylvania in 1994.
Context: Santorum served in the United States Senate representing Pennsylvania from 1995 to 2007. From 2001 until 2007, he was the Senate's third-ranking Republican. He was first elected to the Senate during the 1994 Republican takeover, narrowly defeating incumbent Democrat Harris Wofford, 49% to 47%. The theme of Santorum's 1994 campaign signs was "Join the Fight!" During the race, he was considered an underdog, as his opponent was 32 years his senior. He was reelected in 2000, defeating U.S. Congressman Ron Klink by a 52-46% margin. In his reelection bid of 2006, he lost to Democrat Bob Casey, Jr. by a 59-41% margin.  After his election to the Senate in 1994, Santorum sought to "practice what [he] preached" and hired five people for his staff who were on welfare, food stamps, or other government aid.  In 1996, Santorum served as Chairman of the Republican Party Task Force on Welfare Reform, and contributed to legislation that became the Personal Responsibility and Work Opportunity Act. Santorum was an author and the floor manager of the bill. In 1996, Santorum endorsed moderate Republican Arlen Specter in his short-lived campaign for president. Reporters have observed that though Santorum and Specter differed on social policy, Specter provided him with key political staff for his successful run in 1994.  The National Taxpayers Union, a fiscal conservative organization, gave Santorum an "A-" score for his votes on fiscal issues, meaning that he was one of "the strongest supporters of responsible tax and spending policies" during his tenure, and ranked fifth in the group's rankings out of 50 senators who served at the same time.
Question: What years did he serve as chairman?

Answer:
1996,