I removed your stats from your post, per Google's TOS. But I saw what you were asking and can answer. The number you are referring to is the "Effective CPM". That is the rate you are earning per thousand impressions.
For example, if you showed 2000 impressions in a day and earned $10, your Effective CPM would be $5 (you earned $5 per 1000, $5 x 2 thousand = 10) Likewise, if you only showed only 100 impressions and earned $.50, your Effective CPM would also be $5 ($5 x 1/10th of a thousand = $.50)