19. The mammal with the longest lifespan on Earth is the bowhead whale. There are 10 bowhead whales, and this year their ages are consecutive natural numbers starting from 209 to 218. Then, when the youngest bowhead whale is $\qquad$ years old, the sum of the ages of these 10 bowhead whales will be 2020 years less than the sum of their ages this year.
$7$