Annual power losses

[Ruhaizad Ishak]

Dear All,
 
I am new in using this Matpower tool and wish someone could guide me on how to 
calculate annual power losses (52 weeks) for IEEE 24 bus system.
 
How can I pose different set of load values to the system and then calculate 
the total losses of the test system. 
 
Similarly, I also wish to define a generation profile to each generator for eg 
Week 1: Generator 1, 50 MW; Week 2: Generator 1, 70 MW and etc. 
 
Thank you in advance for your kind assistance.