Dunkley byelection, page-457

Voter turnout 74.55%
below average...

Voter turnout[12]

During the period of voluntary voting (1901–1924) the average turnout for by-elections was just 56.7 per cent. The lowest figure was 15.1 per cent in East Sydney in 1903. Since the introduction of compulsory voting in 1924 the average by-election turnout figure has been 87.3 per cent. This contrasts with a 94.4 per cent turnout in general elections over that period.

During the compulsory voting years there has been a slight fall in the by-election turnout figure. Prior to 1970 the turnout in 62 by-elections was 88.5 per cent; the turnout for the 55 by-elections since 1970 has been 86.1 per cent. The lowest turnout figure over the compulsory voting period has been 69.5 per cent in Wentworth in 1981. Remarkably, there have been three by-elections in this electorate (1956, 1981 and 1995) and the average turnout has been only 75.9 per cent.

https://www.aph.gov.au/About_Parliament/Parliamentary_departments/Parliamentary_Library/pubs/rp/rp1718/HoRByElections#_Toc507065025