I can give an estimate - about 1125 hours for Oct-March.
Average for 1981-2010 is 1271, so well below that.
Average 1949-2010 (Ch'ch Aero site) is less at 1220, still a significant but not huge drop.
Highest value was 1477 in 2002-03, lowest at that site was 1036 in 1952-53, similar to W'gton's new record low.
A tally of just 733 hours in 1936-37 at Waimate makes these numbers look quite good!