Pattern Help!

Can someone translate this for me? I especially don’t understand how to make sense of the part in parenthesis. I thought that it went from XS to XL, but why do the numbers get smaller instead of larger? Here’s what I am talking about: Row 1 (RS): K0(2:5:0:2), (K2tog, k7,yfwd)1(1:1:0:0)times* K1, yfwd, K7,sl 2 ;K1,p2sso,K7,yfwd, rep from* to last 10(12:15:1:3)sts,(K1
yfwd,K7,k2tog tbl) 1 (1:1:0:0)times, K0 (2:5:1:3).
I would be making a medium and it is a Rowan pattern from the Calmer book (Shadow). Thanks!

The numbers change according to the stitch pattern. In some sizes the CO number will fit into the pattern better and you don’t have to put in extra stitches on the ends of the row, like you might with other sizes, or the number of repeats work out better. Just circle or mark the numbers for your size and you’ll be fine.