Printing issue in sr.no

Hi expert,

I have a problem in service entry report in printing in Sr.no. It print 1 to 9 corect but afert 9 it will count agian 0 to 9 like this: 1,2,3,4,5,6,7,8,9,0,1,2,. While i want to print it like this: 1,2,3,4,5,6,7,8,9,10,11,12. Expert please sugest me what should i do ?

Given is the print preview.