blah blah blah,
You might have that the wrong way around. If by bus, you mean A320. Most people are currently doing 8-9 years as S/O before becoming an A320 F/O. Previously there was the option of 737 FO as an entry level position, or a jump sideways from SO, but with the 737 exiting the fleet soon, that option is all but gone. However, in the past, people have got 737 commands, and 767 FO jobs in as little as 3 years from joining. As mentioned above, there are slow patches, and fast patches. Air NZ's slow patches are worse than others though. There are a lot of A320's due in the next few years, as well as a few 787's coming so fingers crossed this is the start of an upswing.