Elections to the council are held in three out of every four years, with one third of seats on the council being elected at each election. Since the first election in 1973, the Conservative party and the Liberal Democrats have had periods in control. The Conservatives had a majority from 1973 to 1984, and then again from 1998 to 1991 after a period of no overall control. The Liberal Democrats won control in 1994 but lost their majority in 1999. They had control from 2006 to 2007 and from 2008 to 2011. In the 2011 election the Conservatives took half the seats, with 29 councillors.