You can make a bar chart of SW WA rain here - and note how after 1975 there has been a lack of "high rain years". So some WA wheat croppers could recall those wet years pre-1975. http://reg.bom.gov.au/cgi-bin/climate/change/timeseries.cgi?graph=rain&area=swaus&season=0112&ave_yr=0
The BoM contour map of "Thirty-six-monthly rainfall totals for Australia" that MikeMennell linked to takes into account SW WA rainfall from the high rain pre 1975 period so naturally has that dry look. IMHO a more useful map would ignore the pre-1975 high rain data and just rate SW WA rain on post 1975 numbers - because "that is the rain regime we are in" and crop farmers have to work with. My chart of WA wheat production shows two good years and a poor year in the period of the "Thirty-six-monthly rainfall totals for Australia" BoM map MikeMennell linked to. So maybe WA wheat growers are getting smarter at growing their wheat too. So MikeMennell - when you say - "Illustrates how dry SWWA has been!!" It might be more informative to say - "Illustrates how dry SWWA has been!! - taking into account the many very wet years pre-1975"