Google backlink and Pr update

My site is still pr 0 obviously as I am brand new to this industry it takes time. How long did it take you to move from pr 0 to pr 1 and how long did it take the rest of you? I understand it depends on SEO linking, content etc but just wanted to get a general idea.

I started my site in September 06 and 2 months ago I received a PR1 on most of my inside pages.

Officially I started my site in September, 2005, in two months I got PR1, after in three months I got PR2, after only in 8 months I got PR4 and after that in 2 or 3 months I got PR5.

My site had been having PR2 for a long time, because I did very bad link exchanges, I thought If I exchanged links as more as possible my PR would increase, and I didn’t pay attention on the quality of these links. After a year I understood that the quality of links and the quality of sites which gave me reciprocal links were very important and I started to do several link exchanges per day with only high quality sites, they could offer me PR0 reciprocal link but if I saw that these sites were very good and they weren’t like banner farm I would exchange links with them.