
The graph gives the estimated population , in thousands, of a town years since 2010, where . Which of the following best describes the relationship between the estimated population at and ?
The estimated population at is 1.5 times the estimated population at .
The estimated population at is 2 times the estimated population at .
The estimated population at is 2.5 times the estimated population at .
The estimated population at is 4 times the estimated population at .