Translation:I eat ramen every year.
"maitoshi" is much more common, but "mainen" is also used and is not wrong.
edit: My source is I live in Japan and I asked a handful of Japanese people what they think is more common. They all said "maitoshi" is the more common one. It seems like a lot of websites are reporting that "mainen" is more common. I'm guessing that is probably because websites which count frequency of words usually do so by sourcing newspapers and books, and therefore are screwed more towards literary language. But that's just conjecture.
That site gets its info from texts, and who knows from where. Native speaker from the Tokyo area says definitely "maitoshi." However, other parts of the country could differ. Everyone commenting should specify which city they are from. There are a lot of differences just between Tokyo and Osaka, and in the north and south there are even more. So, you can't just always say you live in Japan and this is the way it is.
I agree that each region has a "more common" way of saying things. I think as a language learner, we need to be aware that there are different ways of saying one thing, and we can't say that one is wrong just by knowing that the other is right. Personally I prefer まいとし over まいねん (I am not living in Japan now but I used to live in Fukuoka.)
I understand that to many people the Japanese らりるれろ sounds more like an "l" (and in fact the placement of the tongue is closer to that of an "l"), but all of the most common romaji systems translate it as an "r". Most importantly, "ramen" is now an English word, and this is asking for an English translation.