Continuing in St st, increase 1 st at each end every 6 rows 2 (4, x, x, x, x) times, each end every 4 rows 13 (10, 16, 16, 15, 14) times, and then every 2 rows x (x, x, 2, 2, 4) times – 60 (60, 64, 68, 68, 72) sts on last row worked.**
After the ribbing, increase at each end on rows 6, 12,18,and 24. Then on rows 28,32,36,40,44,48,52,56,60 and 64. That should bring you to 60sts. Remember that there are 2 increases per increase row.