Yes, they can only check the last 5 years at the time you apply. Do not apply for PR card renewal until you have 730 days or more in Canada and can prove it. You can not leave Canada during this time as you will not have a valid PR card to get back and you would risk not being let back in.
For persons who have been permanent residents of Canada for more than five years, the only
five-year period that can be considered in calculating whether an applicant has met the residency
obligation is the one immediately before the application is received in the visa office. A28(2)(b)(ii)
precludes a visa officer from examining any period other than the most recent five-year period
immediately before the date of receipt of the application.
Even if a person had resided away from Canada for many years, but returned to Canada and
resided there for a minimum of 730 days during the last five years, that person would comply with
the residency obligation and remain a permanent resident. An officer is not permitted to consider
just any five-year period in the applicant's past, but must always assess the most recent five-year
period preceding the receipt of the application.