Which statement is true of the graph on the right?

The average salary doubled between year 1 and 2.

The average salary tripled between year 1 and 3.

The average salary increased by the same amount each year.
A bar graph entitled Average salary in dollars has year on the x-axis, and salary on the y-axis from 40,000 to 48,000, in increments of 2,000. In year 1 the salary was 43,000. In year 2 the salary was 45,000. In year 3 the salary was 47,000.