Band 9: The graph below shows the population change between 1940 and 2000 in three different counties in the U.S. state of Oregon. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

The line graph compares the populations of three counties in the U.S. state of Oregon – Columbia, Yamhill and Washington – between 1940 and 2000.

Overall, the populations of all three counties increased over the 60-year period. Washington consistently had by far the largest population and experienced the most dramatic growth, while Columbia and Yamhill remained significantly smaller, with Yamhill maintaining a slight lead over Columbia throughout.

In 1940, Columbia’s population stood at approximately 25,000, compared with around 30,000 in Yamhill. Over the next three decades, both counties experienced moderate growth, reaching roughly 35,000 and 40,000 respectively by 1970. Their populations then rose more noticeably, finishing at about 75,000 for Columbia and 90,000 for Yamhill in 2000.

Washington began with a considerably larger population of around 75,000 in 1940. This figure increased steadily to approximately 120,000 by 1970 before rising sharply over the following three decades to reach about 240,000 in 2000, making it by far the most populous county throughout the period.