What is the formula for calculating GATE score?

GATE Score = 1000/100{ag+sg(m-a)/s)} where,m : marks obtained by the candidate. a: average of marks of all candidates who appeared in the paper mentioned on this scorecard in GATE 2009 s: standard deviation of marks of all candidates who appeared in the paper mentioned on this scorecard in GATE 2009 ag: average (global) of marks of all candidates who appeared across all papers and years 2006-2009 sg: standard deviation (global) of marks of all candidates who appeared across all papers and years 2006- 2009 The maximum score can be 1000.