The Swedish Social Democratic Party has played a leading political role since 1917, after Reformists confirmed their strength and the revolutionaries left the party. After 1932, the Cabinets have been dominated by the Social Democrats. Only five general elections (1976, 1979, 1991, 2006 and 2010) have given the centre-right bloc enough seats in the Riksdag to form a government. This is considered one reason for the Swedish post-war welfare state, with a government expenditure of slightly more than 50% of the gross domestic product.