From 7/25/1953 to 6/7/1981 is: 334.433 months
http://en.wikipedia.org/wiki/Robert_Zoellick
Robert Bruce Zoellick (born July 25, 1953) was a United States Deputy Secretary of State, resigning on July 7, 2006. Before holding this position, he served as United States Trade Representative, from February 7, 2001 until February 22, 2005.
He announced his resignation on June 19, 2006 to join the investment bank Goldman Sachs as a managing director and chairman of the company's International Advisors department.[1]
President George W. Bush nominated Zoellick on 29 May, 2007 to replace Paul Wolfowitz as President of the World Bank.
