Gold output jumped 45 percent in 2016 compared to the previous year as new projects came online and activities expanded across the industry, the Ghana Chamber of Mines said in a report on Friday.

Total gold output from Ghana, Africa’s second largest producer, was 4.1 million ounces, the highest level in nearly 40 years, up from 2.8 million ounces in 2015, the report stated.

Canada’s Asanko Gold, which launched its operations in Ghana late 2015, produced 162,802 ounces of gold last year while US-based Newmont Gold and Anglogold Ashanti’s Iduapriem mine recorded increases in output.

Output from artisanal miners rose nearly six-fold to 1.5 million ounces in 2016 from 267,662 in the previous year.

Total Gold revenues for 2016 including exports from small-scale mining amounted to $5.15 billion up from $3.32 billion in 2015.

Manganese output also rose to 2 million tonnes last year from 1.2 million tonnes, while diamond production slipped to 143,005 carats from 185,376 carats in 2015.