After a downturn in the 1990s during the closure of the gold mines and the downsizing of the government workforce in 1999, Yellowknife's economy has recovered, largely because of the diamond boom; the Ekati Diamond Mine, owned and operated by BHP Billiton (sold to Dominion Diamond Corporation in 2013), opened in 1998. A second mine, Diavik Diamond Mine, began production in 2003. Production from the two operating mines in 2004 was , valued at over C$2.1 billion. This ranked Canada third in world diamond production by value, and sixth by weight. A third mine, the De Beers owned Snap Lake Diamond Mine, received final approval and funding in 2005 and went into production in 2007. De Beers also applied in 2005 for a permit to open the Gahcho Kue Diamond Mine Project on the property formerly known as Kennady Lake. The mine was officially opened on September 20, 2016 and began commercial production in March 2017. As well, growth and expansion in natural gas development and exploration sectors has contributed to this growth. Economic growth in the Northwest Territories was 10.6% in 2003.