First month of the spring book, and last two of winter.
Trends and books are always 3 month rolling averages. The difference is that the books are entirely the ratings period (all 3 months), while the trends reflect the 3 previous months
And of course, it all depends who gets the diarys. A change of .5 or less is negligible. The correct way to read those is to look at the numbers over a year, and see what has happened. If the change is really small, then there is really no difference.
And, niche formats like the Score or ESPN will never rate very high 12+, you need to see the demo breakdowns, where they both do very well.