Deterioration in recent BoM rainfall data

This pioneering weather map from the Sydney Morning Herald 5Feb1877 has a list of 33 towns and locations in New South Wales where daily weather observations, rainfall, max & min temperature, barometric pressure etc were being recorded. 34 if you count Sydney Observatory Hill.
For many years I have been puzzled at the deterioration in BoM rainfall data more recent than about 1995
and this list of heritage NSW weather stations is a useful source to test my 2008 claim on a group of
significant BoM stations choosen by somebody else. For each location name I have searched CDO for monthly
rainfall data from ~1870’s and for sites that closed decades ago to fill gaps. I have added a site or sites till I got data ~current to 2019. I have not cut and pasted every location into a spreadsheet to test for every missing year – that can wait until I have more time.
My spreadsheet records 64 stations used to build a full record for each of the 34 locations – many could be improved by adding data from the closest Airport AWS which might be further away and as I said in the above sentence there may be a few where missing years I have not eyeballed need hunting down from neighbours.
Here is my spreadsheet where marked in red are 22 examples of “post ~1995 gappy data”.
You can check the data for yourself near the bottom of the CDO page where 3: Get the Data invites you to
type the station number and hit the Get Data button. Easy. See examples of the data deterioration –
increasing gaps – for yourself. Modern AWS sites are not immune to data gaps.