Did Google Change Their Pay-Out Rates?

On my Disney site I use Google Ad-Sense which I’ve been doing okay with. I was averaging about a dollar a day which was plenty to cover my server costs and whatever. And I was happy. However,since the first of September, without making any extensive changes to my site, my earnings have increased exponentially, up to 3, 4 or even 5 times what I was making before! This started precisely at the first of September. Did Google change their pay-out structure and did I just miss the memo?