Conversation so far:
What was an education position that Bill Richardson held?
Bill Richardson was an adjunct professor at Harvard University's Kennedy School of Government
What years of Bill Richardson's  life did was he a professor at Harvard University's Kennedy school of government?
Did Bill Richardson have any other educational jobs besides professor at Harvard University's Kennedy school of government?
Bill Richardson was a lecturer at the Armand Hammer United World College of the American West.

Question: How long did he hold that position?
Self-contained rewrite: How long did Bill Richardson hold the position of lecturer at the Armand Hammer United World College of the American West?