You can find the LICO table here:
http://www.cic.gc.ca/English/information/applications/guides/5196E10.asp It is the 3rd table. It shows for example that if you are a family of 4, you need enough income for 4 plus parents so that is 6 people. That would be $52,838 per year.
If your spouse co-signs the application, you can count their income as well.
It takes a long time to process parents. The applications are first processed in Mississauga, currently takes 45 months to approve the sponsor, see
http://www.cic.gc.ca/english/information/times/perm-fc.asp and after that another 42 months in Islamabad so total about 7 years.