Since the end of the Playmander, South Australian politics have been characterised by a concentration of seats in the Adelaide metropolitan area, a manifestation of South Australia's status as the nation's most centralised state. Successive redistributions have resulted in Adelaide and its suburbs containing close to three-quarters of the seats (34 out of 47 in 2017). This makes it difficult to form even a minority government without gaining significant ground in Adelaide. Labor's success in South Australia over the last four decades has been built on a strong base in Adelaide; under normal conditions Labor wins the most seats in the capital. Since the 1975 redistribution, most of the Liberal margin has been locked into ultra-safe rural seats. This remained the case even after the "fairness clause" amendment.