Even so, it was hoped that the output might rise to 500 tons.

By 1794 this had risen to 3,663 ships and 620,845 tons.

With this fleet, the British contribution was expected to rise to 750 tons a day in the short term.

Within 10 years, exports rose to 60 tons per year.

By 1929, this had risen to 83,000 tons per month.

That could rise to 1.5 million tons a year as demand increases, the companies said.

Production is expected to rise to 330,000 tons next year.

In the 1970s, the annual catch rose to between 200,000 and 300,000 tons.

That number is expected to rise to 216 million tons in 2000.

Sorghum production, for example, rose from almost nothing to 2.7 million tons by the end of the decade.