In the A320-200's 'AIRCRAFT CHARACTERISTICS AIRPORT AND MAINTENANCE PLANNING' document. It presents the A320's PL/R capabilities as:
Firstly, I would like to know: What are the 3 different MTOW's listed? Is it for different seating layouts? eg 'high density' vs 'business + economy' or what? Note that 73.5(78) tonnes is the MTOW listed on Airbus's website, seen here, but they don't clearly indicate what the figure in brackets indicates.
Secondly, does the payload axis include passengers as well as cargo? If so, if the maximum amount of passengers is listed as 180, how much additional cargo can the aircraft carry, both in the cargo hold and overhead luggage trays? i.e. what model does the airlines/airframers use to estimate the weight of 180 passengers?