There is no set figure as such, but your CTR is way too low, 3-5% is normal, you will need some more ad optimization.
It depends on the site's type. MFA sites can reach 20%, while community sites will rarely cross the 1% mark.
I think that is too little. You can improve your CTR to a great extent by blending / contrasting your ad with the contents depending on the niche and suitable ad placement. The range is 2-5% and there are people getting more than 10%. Beyond that exercise caution. Good luck...
Under 1% is a bit bad...:/ You need to change your location, your colors etc etc and see if you can get that up to 1% at least.
CTR, for me ranges from less than 1% up to averages of 33% 40 something %, depends on which site. For me, high traffic, low ctr, low paying niche. Low traffic, better ctr, slightly better paying niche. One of my niches, normal to have 100% and 50% ctr for most of the day if receiving traffic. As you can see it differs.
mine is 4-5.7% ...i hope it is fine ? but my eCPM is low compared to it...Something around $2.5....is it low ?