Can't I do back test in PI for more than 1 year

Even if I am asking to backtest for 59 months the results are given from 2/2/15 till date. Can’t I do back testing for longer period say 5 or 10 years.

You can do backtesting ony for as long as the data is present. My guess is that the scrip you are backtesting for has data only from 2nd Feb.