At the current extraction rate, this would last 132 years.

And at today's extraction rates, there's another 40 years-worth (£1 Trillion) left.

Any given site does not last very long - four or five years at extraction rates of up to a quarter-million tons a year.

The reserves were expected to last for another 15 years as of 2010 at the extraction rate of 1,433 metric tons of concentrate.

The extraction rate is almost constant, and only flattens off towards the end of the extraction.

These modifications included improvements to Foremost's accuracy and extraction rates.

Flour made from all parts of the grain (extraction rate: 100%) leaves about 2 g ash or more per 100 g dry flour.

Plain white flour (extraction rate: 50-60%) leaves only about 0.4 g.

In general, as the extraction rate of the flour increases, so do both the protein and the ash content.

The lightest forms tend to result in higher extraction rates.