[tz] 'Australia/Canberra' time zone?

Hi there I have been a bit surprised that the TZDATA database lacks a listing for "Australia/Canberra", population 350,000. What is the basis for deciding which cities are included or excluded from the database? Does being the national capital, and the major city in its own state/territory warrant inclusion, or is there another criterion? Here is what I believe to be an official source about the Canberra timezone (at least for the present day): https://www.australia.gov.au/about-australia/facts-and-figures/time-zones-an... Cheers JP