The International Maritime Bureau says that attacks on commercial ships by Somali pirates have dwindled this year.

The bureau said Somali pirates attacked 69 commercial vessels in the first half of this year, less than half of the 163 attacks during the first half of 2011.

Somali pirates hijacked 13 ships in the first six months of 2012, a far cry from the 21 vessels hijacked during the same period last year.

However, the bureau added that pirate attacks have tripled in waters off of West Africa, such as the Gulf of Guinea and off the coast of Nigeria and Togo.