[4] In 1986, the seat had 9,410 enrolled voters compared with an average of 13,796 statewide and over 28,000 in some metropolitan electorates such as Joondalup and Murdoch.The Burke Labor government's Acts Amendment (Electoral Reform) Act 1987, passed with National Party support, increased metropolitan representation from 29 to 34 out of 57 seats, and the 1988 redistribution which resulted in Collie gaining parts of Dale and Warren combined with a significant statewide swing against the Labor Party delivered the seat to the Nationals' Dr Hilda Turnbull, who held the seat until the 2001 election.By 1968, the seat consisted of the Shires of Collie, Donnybrook-Balingup and Boyup Brook districts, and from 1976 to 1982 also included Dardanup.The 1994 redistribution added Dardanup and eastern Capel, including Boyanup but excluding Eaton and the coastal regions.Ahead of the state election, only Collie and Dardanup were retained, with the seat gaining Waroona and most of Harvey (excluding Australind and other urban districts which were part of Leschenault).