Read this and answer the question. If the question is unanswerable, say "unanswerable".

In addition to the mentioned late local newscasts, CBC stations in most markets fill early evenings with local news programs, generally from 5:00 p.m. to 6:30 p.m., while most stations also air a single local newscast on weekend evenings (comprising a supper hour broadcast on Saturdays and a late evening newscast on Sundays). Other newscasts include parts of CBC News Now airing weekday at 6:00 a.m. and noon. Weekly newsmagazine the fifth estate is also a CBC mainstay, as are documentary series such as Doc Zone.

What weekly newsmagizine has played since the inception of the CBC station?
unanswerable