Residence Obligation:
1. PR more than 5 years - you must have 730 days in the 5 year period looking back in respect of any examination where 'examination' means any interaction with CIC/CBSA e.g. port of entry admission, PR Card renewal, Sponsorship etc. (historic looking timeline)
2. PR less than 5 years - you must be able to have 730 days by the 5th anniversary of your landing at any examination. (forward looking timeline)
PR timeline counts from landing date not PR Card issuance date. the 730 days do not have to be consecutive.
There are exceptions for various categories e.g accompanying a Canadian Citizens spouse, serving in the military etc.