It's very difficult to tell exactly. I was hired in February with 4000TT and only 140 TPIC, however I have a Master in Engineering and lots of volunteer work and a very favorable education history. They have a matrix which awards "points" for any number of things (including completeness of the app) and if you score enough points you get an interview. What they give points for and how much you need are closely held secrets you won't find anywhere. Just fill out the app as completely as possible and get someone to send an email to pilot selection to have the app scored. Keep in mind that the scoring is entirely manual so it may take some time to do it. They post internally that it can take up to 30 days to do a scoring and they will only score an app once every 12 months.

Best of luck!