You have a 150 years of statistics ... does none of it demonstrate your claim? ... quit explaining yourself, I understood you the first time ... rainfall RATES per unit time are increasing ... I even explained what could cause this to happen ...
So let's dumb this down more ... an increase in temperature won't cause this ... something else has changed, my guess is that you've started to pay attention to the weather ... and are just now noticing rainfall rates ... truth is things have always been this way, and I can say for certainty that an inch of rain in 25 minutes is common in Eastern Iowa in the 1980's ...
Here in Western Oregon, it rains every day all day long ... but only a quarter inch per day usually ... I remember one Pineapple Express that laid down a whole SIX INCHES in just one weekend ... flooded everything ...