Shown with a cast-on count of 21 stitches.  

• Row 1 (RS): [K1, p1] 3 times, k4, yo, k1, yo, k4, [p1, k1] 3 times (23 sts).
• Row 2: [K1, p1] 3 times, p11, [p1, k1] 3 times.
• Row 3: [K1, p1] 3 times, k4, yo, k3, yo, k4, [p1, k1] 3 times (25 sts).
• Row 4: [K1, p1] 3 times, p13, [p1, k1] 3 times.
• Row 5: [K1, p1] 3 times, k4, yo, k5, yo, k4, [p1, k1] 3 times (27 sts).
• Row 6: [K1, p1] 3 times, p15, [p1, k1] 3 times.
• Row 7: [K1, p1] 3 times, k7, yo, k1, yo, k7, [p1, k1] 3 times (29 sts).
• Row 8: [K1, p1] 3 times, p17, [p1, k1] 3 times.
• Row 9: [K1, p1] 3 times, k7, yo, k3, yo, k7, [p1, k1] 3 times (31 sts).
• Row 10: [K1, p1] 3 times, p19, [p1, k1] 3 times.
• Row 11: [K1, p1] 3 times, k7, yo, k5, yo, k7, [p1, k1] 3 times (33 sts).
• Row 12: [K1, p1] 3 times, p21, [p1, k1] 3 times.