I’ve prepared a chart showing the twenty year ‘life cycle’ of the approximately 30,000 patent applications filed in 1992 and expired in 2012 from filing and examination to grant and abandonment. While approximately 13,000 applications (about 45%) resulted in issued patents, only about 4,000 were still in force after 20 years.

This chart is based on CIPO’s “tombstone” and financial data for patent applications filed in 1992 (either filed in Canada or filed as a PCT application which subsequently entered Canada). There is about a 2% increase in the number of applications over the 20 years because of divisional applications.

The large purple area in the bottom right represents applications which are abandoned without ever being granted, either because of missed maintenance fees or failure to respond to patent office requisitions. The dark blue in the top right represents applications which granted to patent but were not maintained by paying the annual maintenance fees.

The small green area in the bottom left represents PCT applications which haven’t entered national phase in Canada yet. In more recent years, there will be more significantly more PCT filings (about 75% in 2012) as compared to about 32% in 1992.

The sharp drop in “Pending” applications at the end of year seven is caused by the requirement at the time that examination be requested after a maximum of seven years from filing (the Rules changed in 1996 to require examination after five years).

The annual steps in both the dark blue and purple areas indicate applications or granted patents which are abandoned for failure to pay annual maintenance fees. Note that prior to 1996, there was a six month reinstatement period but since 1996 a twelve month reinstatement period applies.

The red area indicates applications under examination (either in the queue for examination or in active examination). A small number of applications remained in examination until their expiry (see for example 2,121,127) and the last issued patent from this cohort issued only about 150 days before it expired.

From my review of the litigation proceedings, about 70 of the patent applications filed in 1992 were involved in litigation in the Federal Court, with the most litigated being 2,072,945 relating to Rosuvastatin/CRESTOR.

Below is an interesting comparison chart for the approximate 660 patent applications filed in 1992 without a patent agent. Only 90 issued to patents (about 14% of those filed) and only two patents were still maintained after 20 years. Almost 45% of the patent applications filed without an agent were abandoned after the first maintenance wasn’t paid.