But the price also reflects heavy production from oil producers.
In years of heavy production, men control the income.
But, under the heavy production there is also a pop song buried here.
Zinc and lead mining were in heavy production through the 1820s - 1920s.
Following decades of heavy production, the timber harvest on public lands has declined by more than half in the last 10 years.
The town of Mauldin first began heavy production of timber in 1922.
She also criticized the "heavy" production, and gave the song a "thumbs down".
It is an important tree in Japan for its heavy production of sweet, edible nuts.
With heavy agricultural production comes the need to transport it.
These cities prospered through heavy production even after the end of the war.