Shown with a cast-on count of 9 stitches.  

• Row 1 (RS): K2, yo, kfb, k3, kfb, k2 (12 sts).
• Row 2: K2, yo, kfb, k6, kfb, k2 (15 sts).
• Row 3: K2, kfb, k9, kfb, k2 (17 sts).
• Row 4: K2, kfb, k11, kfb, k2 (19 sts).
• Row 5: K2, yo, kfb, k13, kfb, k2 (22 sts).
• Row 6: K2, yo, kfb, k16, kfb, k2 (25 sts).
• Row 7: K2, kfb, k19, kfb, k2 (27 sts).
• Row 8: K2, kfb, k21, kfb, k2 (29 sts).
• Row 9: K2, yo, kfb, k23, kfb, k2 (32 sts).
• Row 10: K2, yo, kfb, k26, kfb, k2 (35 sts).
• Row 11: K2, kfb, k29, kfb, k2 (37 sts).
• Row 13: K2, kfb, k31, kfb, k2 (39 sts).