Nigeria’s foreign reserves continued to pile up in January, rising for the third month in a row.

The foreign reserves reached $40.4 billion, an increase of $1 billion from December according to the central bank on Monday.

Successful debt sales, including multiple Eurobond offerings last year, have helped the government accrue billions of dollars in foreign reserves.

The central bank also said it had injected $210 million into the interbank foreign exchange market on Monday, extending efforts to increase liquidity and alleviate dollar shortages.

The  policies ensures decline in Nigeria’s import bills from over $5 billion monthly in 2015 to about $1.5 billion in 2017.