No. See, every time Ash goes to a new region, he finds another Pikachu to replace his old Pikachu. This is why Pikachu always seems to be back at Level 5 whenever he starts his journey.
That is quite the good question. Perhaps they just decide to bring Pikachu back down to level 5, so he doesn't go around bombing everything in the new region? The anime is a bit silly sometimes. I mean, we could always say that there aren't any levels, but during the first Pokemon League, Bulbasaur was fried by Electabuzz because apparently Electabuzzes level was much higher (according to Brock).
If the Anime wasn't being silly, probably mid-70s, at least.