He people we are just talking about amounts of money earned which depends on many factors and that doesn't really help anyone. What about info on % increase per month compared to your previous month beginning from start or a certain period of time? Is that against the TOS?
Sometimes you can also do weeks of work to make sure that you match your last months income, its all relative. Last month I tweaked and work on my sites to get better CTR and I have a better CPC which strangely just went up at the start of May, traffic is down a bit but income remains on track and just slightly higher on the months before. Moving $10 per month to a % increase as apposed to $5000 per month doesn't really compare the efforts involved.
From the beginning one and a half years ago I average a monthly increase of over 30% per month. During the months of summer holidays traffic is slowing down a bit.