I've heard that for BB7, the premiere got 7.69m, down from BB6's average and that the final got 3.5m. That's all I can find of ratings. It's not much to compare it with though. This years have been:
1. Thursday 5th July - 7.4m
2. Sunday 8th July - 6.05m
3. Tuesday 10th July - 6.98m
4. Thursday 12th July - 6.51m
5. Sunday 15th July - 6.51m
6. Tuesday 17th July - 6.98m
7. Thursday 19th July - 7.29m
8. Sunday 22nd July - 6.51m
9. Tuesday 24th July - 6.98m
10. Thursday 26th July - 7.08m
11. Sunday 29th July - 6.36m
12. Tuesday 31st July - 7.29m
13. Thursday 2nd Aug - 7.13m
14. Sunday 5th Aug - 7.76m
15. Tuesday 7th Aug - 7.29m
16. Thursday 9th Aug - 8.03m
17. Sunday 12th Aug - 8.03m
I was hoping someone had something like this for the previous BB's to compare this season to them.