Confidentiality. You agree not to disclose Google Confidential Information without Google's prior written consent. "Google Confidential Information" includes without limitation: (a) all Google software, technology, programming, specifications, materials, guidelines and documentation relating to the Program; (b) clickthrough rates or other statistics relating to Property performance in the Program provided to You by Google; and (c) any other information designated in writing by Google as "Confidential" or an equivalent designation. However, You may accurately disclose the amount of Google’s gross payments to You pursuant to the Program. Google Confidential Information does not include information that has become publicly known through no breach by You or Google, or information that has been (i) independently developed without access to Google Confidential Information, as evidenced in writing; (ii) rightfully received by You from a third party; or (iii) required to be disclosed by law or by a governmental authority.
As you can see, Google does not allow you to disclose any information about your CTR, but you are allowed to discuss your gross payments. Basically, you can reveal your number of impressions, and how much you were paid. You can’t discuss anything related to your CTR.
If you must discuss your CTR with others, you should discuss it in terms of saying things like, “My CTR is well under double digits, and I’m seeking to improve it.” Don’t give exact numbers or ranges. You don’t want to risk your account, and the AdSense rules aren’t terribly clear about what you can and can’t discuss. It’s better to be safe than sorry. Your traffic statistics are your own, so you can discuss impressions. The amount you are paid is specifically allowed to be discussed in the terms. Anything else should be considered off limits just to be on the safe side.