Complex sentence: The outcry over this result led Hall to institute electoral reform that saw the establishment of 47 single-member electorates in 1968--28 in Adelaide and 19 in rural areas, an increase of 15 metropolitan seats, more than double.
Split into simpler sentences: The outcry over this result led Hall to institute electoral reform in 1968. The House was expanded to 47 seats--28 in Adelaide and 19 in rural areas, an increase of 15 metropolitan seats, more than double.