The Scottish Parliament is the devolved legislature of Scotland. It was founded in 1999. The 129 members of the Scottish Parliament (MSPs) are elected using the additional member system. 73 MSPs are elected through the first-past-the-post system in the Parliament's single-member constituencies, while 56 are elected in the regions to ensure results are proportional. There are 8 regions, electing 7 MSPs each. By-elections to the Parliament occur when a constituency seat becomes vacant, due to the death or resignation of a member.