Rotational Players - How long does it take you to rotate through every sim?

I play over 30 households in my rotation, but it's irregular and I dare say it might take me a year to play every sim I consider "played". But like said the amount how long I play them and how I rotate is irregular so... it's really hard to estimate.

edit: I suppose I could have also said I don't rotate really as I also change who is "played", drop into families randomly etc.