But this year, the miners ran into problems underground and production suddenly slumped.
About 1,200 D4s were produced between 1950 and 1953, but in 1953 production had slumped to just 110.
Industrial production slumped in May, and is at its lowest level since December 2001.
Annual production slumped from 1,365,000 bales in the 1910s to 801,000 in the 1920s.
As a result, production slumped by 23% in 2000 and remained stagnant in 2001.
While government revenue initially rose as oil prices soared, production soon slumped.
Unemployment jumped from 5.2 percent to 5.9, and industrial production slumped.
The field, whose production had slumped to 10,000 barrels a day in the 1960s, now has a daily output of 85,000 barrels.
However, his production slumped last season, when he missed five games because of an injury and finished with 23 catches.
Unemployment rose from 7.5 million to nearly 10.5 million in 1938 as industrial production slumped.
