Another Australian math question.?

Here's a bit of maths to think about.

When decimal currency came in, in February 1966, these items were the same price -- 33 cents (converted from 3 shillings & fourpence):

Gallon of petrol (4.5 litres to the imperial gallon)

Packet of 20 cigarettes

One large bottle of beer (ie price of box of 12 'largies' 740ml bottles divided by 12)

What's gone up the most over the last 40 years?

Not petrol. Surprised?