Complex sentence: Milton expanded considerably in the late 1980s when two large housing estates were built between the bypass and the village resulting in a doubling of the population between the 1981 and 1991 censuses.
Split into simpler sentences: Milton expanded considerably in the late 1980s when two large housing estates were built between the bypass and the village. This resulted in a doubling of the population between the 1981 and 1991 censuses.