Yes and this could be used to reduce the casino income, as in a dirty casino would be unpopular with the potential customers. So 100% dirty would get the maximum penalty, and a totally clean one no penalty.

Well the digit in the pie chart shows between 0 to 100 (which is the inversed of the graph). You would think the graph shows this number, like it does with security, popularity and happiness... no? They way the cleanliness graph works now is the dirtier the higher the number.. whereas it is called cleanliness, so the cleaner the better (as 100 would be 100% clean). Which is used this way in the pie chart.

The maximum rubbish seems to be 2000?

It plots the cleanliness, zero rubbish = zero on graph? It does what it says on the tin, what's the problem? Or to put it another way, how would you work it as a percentage? as there is no maximum, or none that I spotted in the three days it took me to realise I needed to hire a janitor :D