That's odd, because I originally thought that looked like Adsense's "smart pricing" (where Adsense reduces the value of all clicks down to pennies) but smart pricing is only activated when your site has lower than a 5% CTR (in order to insure "quality for advertisers"). There is a possibility that Adsense thinks some of those clicks are fraudulent or something. I'm not saying they are, but Adsense has a penchant for being a little too automated.
Good news and bad news... your 16%CTR is amazing. However, i think you shall make some changing on the keyword so that the CPC will increase
i think u r having celebrity content...... so $ 0.022 is ok for that. if you are looking for more revenue, make contents regarding UK flats ($0.45-$0.75), newzealand jobs (upto $2) (with practical knowledge, i got this amount)
Are you clicking your own ads? It's a very high CTR and to get that little average CPC you must be receiving quite a few invalid clicks.