SQL & PL/SQL :: How To Increment Count When GROUP By Is Used

SNO column should be incremented depending upon the total records to be fetched.if i get 4 records then sno numbers should be 1,2,3,4.i dont want to put rownum also in the GROUP BY clause.how to increment the serial number?

SELECT JC.A,
ROWNUM SNO, --serial number
JC.B,
SUM(CHR.AMOUNT),
SUM(CHR.FINALAMOUNT),
JC.C,
JC.D,
C.E,
JC.F,
JC.G
FROM CHARGES CHR
WHERE JC.B = '12111'
AND JC.STATUS = 'INVOICED'
GROUP BY JC.A, JC.B, JC.C, JC.D, JC.E, JC.F, JC.G;