I tracked the 42,000 or so patent applications in Canada with a 2001 filing date which all expired by the end of 2021. Only about 17% were still enforceable at expiry but about 30% were in force at the 10 year mark. Overall, about 43% of the original applications (about 18,000) were granted and 118 were litigated in the Federal Court.
This graph was prepared from CIPO patent data for the 41,638 applications with a 2001 filing date.
Approximately 60% of the applications originated as PCT applications (green). Many applications entered examination immediately (navy blue) but all applications had entered examination by 2006 (5 years from filing date), except for a small number of divisional applications which would enter examination as soon as they are filed. Even after 20 years, a few applications were still in examination until they expired – see for example CA2,396,264.
Most applications were abandoned without being granted (red), either because annual maintenance fees were not paid, or the applications were rejected during examination (or both). Some applications were abandoned after granted (cyan) when annual maintenance fees were not paid.