In 1840 the mine was employing 1,174 people, but it closed between 1848 and 1853.

The mine had employed more than 100 people in an area where unemployment approaches 20 percent.

In 2009, the mine employed just over 800 people.

In 2009, the mine employed 578 people, all of which were permanent employees.

The mine employed about 600 workers at the time of the closure.

The mine employed 562 people in 2009, of which 367 were permanent employees.

The mine employs approximately 140 people as of February 2012.

In 2009, the mine employed close to 3,000 people, 2,250 of those being permanent staff.

In 1842 the mine employed 127 workers; by 1959 this had fallen to 40.

At its peak in the early 20th century, the mine employed over 2,000 workers.