From the Knit Rowan website:
Knit this ladies slipover with all over cable pattern from Elegant Knits. Designed by Martin Storey using the wonderful yarn Pure Wool 4ply (wool), this knitting pattern is generously sized to fit up to 48 inch bust.

Finished chest width dimensions:
52: 58: 63.5 cm
20½: 22½: 25 inches

Yarn Information:
Photographed in Blue Iris 455
12, 13, 14 skeins
2088, 2262, 2436 yards