DASH Masternode rewards explained

I am a huge fan of the dash project. I really like there focus on the usability and with "evolution" upcoming and a huge marketing budget which waits to be spend after the release of evolution I am very bullish on DASH.

That said I recognized that DASH masternode payments declined significantly the last weeks and I was wondering why.

Masternode number didn't increase in that amount that it would have explained the decline.

Luckily I have some contact to the dash core team so I asked them what is going on.
From dash core developer Slawek the following explanation came:

Dash in its protocol instead of doing a halving each 4 years has less drastic decline on the reward of -7.14% a year.
The last one happened on 22nd march of 2018 and the actual minimum of MN/miner payout is 1.67 dash, before it was 1.81 dash but it does not mean it will be this low
all the time as if difficulty goes lower then the reward goes up in the quantity of coins and if there are more transactions in the certain block the reward is growing too.

So the block reward just got cut off by 7.14% which perfectly explains my observation. And it will be every year. So next year the minimum reward will be 1.55 dash for masternodes.

But the last part made me wonder. I get that difficulty increases rewards in a given time period for Masternodes as in that time more blocks are found.
But what wasn't so obvious to me in the first place is that also the number of transaction matter. So it seems that also transaction fee are split between miners / masternodes / projects (ratio is 45%/45%/10%). So in case utilization of DASH goes up so does the masternode rewards.

I hope that helped making masternode rewards understandable.