return on equity17 Nov 2013 17:57
net profit / average shareholder equity = 2104/12880
= 16.3%
a note on operating income mentioned earlier:
"The most common reason for high operating margins relative to competitors is a low-cost operating model, which means that a company can deliver merchandise or services to customers at much cheaper prices than competitors and still make money. The classic example is Wal-Mart, which is able to get everything from toothpaste to socks into its store at far lower prices due to the efficiency of its warehouse distribution system"