If I could just add a bit more depth to this issue. In the most simple terms. All the time most of us have been with PB mining, we been in a steep rising difficulty.
Until only recently when we have reached this Plato. What does this mean? It means that all this time we have been solving blocks faster than we than what is planned. , therefore payment to miners was higher.
Your earnings are dependent on difficulty, not the actual network hashrate.