Over the last decade, specifically from 2002 to 2014, the Central Bank of Nigeria has sold $217.2billion to sustain the value of the naira. This has been through the Retail Dutch Auction System and Wholesale Dutch Auction System (RDAS & WDAS).

Defending the naira may not be the only reason for dollar sales, but should the CBN at anything fail to sell dollars to meet authorised dollar demand, the naira will fall.

The table below shows data from the CBN representing offers and actual sale of dollars from 2002 till 2014.

Year	FOREX SALES
2002	3,473,897,467.25
2003	9,590,999,321.21
2004	9,667,420,187.10
2005	10,187,345,240.47
2006	9,452,286,240.92
2007	8,642,295,684.08
2008	11,719,550,003.39
2009	22,198,291,435.24
2010	25,091,783,218.62
2011	29,793,823,776.27
2012	18,652,529,328.66
2013	25,591,467,052.57
2014	33,211,512,065.53
Total	217,273,201,021.31

While the comprehensive figure was calculated over a 12 year period, a drastic increase in the sale of dollars only began in 2009, with the overall highest occurring in 2011 and 2014 respectively.

According to Nairametrics, between 2011 and 2014 Nigeria had spent about $107.2 billion through various auctions to defend the naira, 49 percent of the total amount used in meeting official dollar demand.

Despite these attempts, the naira has depreciated significantly against the dollar. For instance in August, 2014 it fell 1.2 percent to N176.30 to a dollar despite the Central Bank of Nigeria’s (CBN) move to raise dollar sales to $250 million.

Analysts tried to associate this fall with the current oil crisis in the country. According to the Head of Research, Sterling Capital, Mr. Sewa Wusu, the entire crisis can be attributed to the falling oil prices. It can be traced to the activities of investors who were reacting to the potential danger should the oil crisis linger on.

However, centred on the data provided above and the recent devaluation of the Nigeria’s currency, the money spent has not exactly salvaged a fall in naira value.