I used to have a CTR for about 2,5 - 3,5% since I asociated my channal with my adsense account a few mounths ago. It somethimes happened to drop to 1 - 1,5% for 1-2 days, but then it raised again. Now since 29 December my CTR started to drop to 1,2 - 0,8%. It's more than 10 days since that and my CTR it's slowly dropping. What might be the problem?