Even though 595RS is a street legal tyre it is more focused towards track use, therefore giving it a fairly short life when compared to a street tyre.
You will find that a relatively soft UHP (ultra high performance) street tyre like the 595 (240 tread wear) should last you about 30,000km if you look after them.
A comfort tyre (not as soft as UHP) is usually around the 420 - 500 treadwear range which will inturn give you around 50,000km of life.
However you do usually sacrifice overall dry grip when you go for a longer life tyre.
The 595 RS has 2 different tread wear ratings depending on size - 140 / 180 which usually results in you getting about 15,000 - 18,000km out of a set (depending on how much time you use them on the track).
I always advise against using the RS on the street as they perform at their best when they are hot and street driving will NOT get them hot enough to reach their full potential, but they are street legal so the choice is yours to make.
(these are estimations based on treadwear and proper tyre maintenance, if you do not rotate your tyres or check pressures regularly you will not get the desired life from them).
I hope this helps