It'll make you realise you should have been worrying much more all through the 1910s, 1920s, 1930s, 1940s, 1950s, 1960s, 1970s, 1980s and 1990s:
Thanks to Bill Mitchell for reminding me.
The source is the Treasury itself. I wrote about it at the time here, as it happens earning a Saturday morning phone call expressing the Opposition's displeasure.
STOP PRESS: The Parliamentary Library have just put out a paper on the topic.
