Band 8+: 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 illustrates the population growth in three counties of Oregon—Columbia, Yamhill, and Washington—from 1940 to 2000.

Overall, Washington experienced the most significant increase in population, while Columbia and Yamhill grew at a more moderate rate throughout the period.

In 1940, Washington’s population stood at 75,000 and followed an upward trend, increasing to 120,000 by 1970. After this, the population rose sharply, reaching just under 250,000 in 2000.

Meanwhile, Columbia and Yamhill followed a similar pattern. In 1940, both counties had a population of approximately 30,000. By 1970, Columbia’s population had risen slightly to 31,000, while Yamhill saw a more noticeable increase to 45,000. This trend continued, with Yamhill’s population climbing to 75,000 by 2000, whereas Columbia’s population grew more modestly, reaching 45,000.