It depends on the processing center. Some are faster than others. IRCC indicates processing time for grant of citizenship applications is 12 months (as of now). If after 12 months, you're not a citizen, then you can start worrying a bit.
BTW, you can order GCMS notes on your file to get some idea what checks etc have been completed so far. Takes atleast 31 days to receive them.
Where to order GCMS notes ?
http://www.cic.gc.ca/english/department/atip/requests-atip.asp
(requests made under the Privacy Act are free)