The graph displays the population of a town, , as a function of the number of years, , since the year 2000. The line shown passes through the points and . Which of the following statements best describes the meaning of the -intercept of the graph?
The population of the town increased by 15,000 people every 10 years.
The population of the town was 15,000 people in the year 2000.
The population of the town is projected to reach 18,000 people in the year 2010.
The average annual increase in the town's population was 1,500 people.
