highest page ecpm in adsense

I do not know what is the highest page ecpm that is allowed in adsense but for my one of the blog my page ecpm is 22.97 and for other blog of my ecpm is just 0.75

This is a high difference but the reason is that my lowest paying blog is about music and my other blog is about blogging, applications, mobiles and all which has page ecpm of about 22.97

The ctr of first blog is comparatively very high which means blogs about tips and tricks have high ctr