150 years ago, due to overhunting, the number of king penguins on South Georgia Island had decreased to just 10,000.

Since then hunting has stopped, and the number of penguins has increased increased exponentially, so that now the number of king penguins is estimated to be 300,000.

In how many years from now (to the nearest year) will the population of king penguins on South Georgia Island have doubled to 600,000?