I have been watching this show with my Amazon Prime account for free the last few weeks, here and there. I'm on series 6 right now. Initially, I vaguely remembered the program from way back in the 1980's PBS late night, I would catch an episode by mere chance in the deepest hours of the night, and think what a funny and strange show!
I'm glad I can watch all the episodes now, and really so far the show gets better and better, and I'm just waiting for the bottom to fall out as I go later into the series, I'm sure the quality will drop, it's inevitable really. Fantastic show though!
It's kind of strange there's only 6 episodes per 'season' or series as it's referred to. And the series are not yearly, there are huge gaps in years from one series to the next.