As I have written before, but can't now find, where we grew up, telephone party lines were common. Our old one was 41W or 41UU. I never saw it written, so I don't know which. A short ring followed by two longer rings would get our attention.
By the time I came more phone aware, most phone numbers were six digits, ** ****. Then along another digit, *** ****. Now **** ****. I don't think the number of land lines would now be increasing at the pace they were. It is now cheaper to have broadband internet than two dial up lines, one for the phone and one for the pc. That was the clinching factor when we switched to broadband in the late nineties.
Before my time, Melbourne phone numbers used to be two letters, followed by mostly four digits e.g. UV 1234.
One phone number that always used to amuse me, and I know some of you will remember it, is Myer Melbourne, our large department store in the city.
Here is the present one for the main switchboard, 9661 1111. Relying on memory here, but only shortly before phone numbers went to seven digits, the Myer number became 61 1111. But for most of the time when I think every phone number in Melbourne had six digits, an old one of ours in Balaclava was 31 4101, the 31 one denoting a connection to an Elwood exchange, Myer stuck with just five digits, 6 1111.
I think this lasted into the nineteen nineties and seems very odd nowadays and did even back then. Do I recall the switchboard used to answer with 'Which department please?'