It is normal. The range is 2-5% but 10% is considered as excellent and over and above 10%, one has to be very careful
Why would you need to be careful? I have websites generating over 10% on a steady basis, I haven't had a single problem. A 4% CTR is considered as good, anything above that is great. As long as you're staying withing the TOS and doing nothing unethical you should be fine.
My Ctr is all over the place. I don't worry about how high or low it is. I just follow the TOS and am thankful for any money I make whether its a few dollars or over a thousand.
2%-4% is a good CTR for Adsense? My March & April CTR for all my sites are at the average of 13%, 2-3 of my sites are always above 20%. So mine's legendary figure?