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

The line graph illustrates the transformation of population in the period of 60 years from 1940 to 2000 in three different countries in the US state of Oregon: Columbia, Yamhill, Washington.
In general, all three countries in the state experienced a significant growth, while the Washington ranked first, Columbia had the lowest population.
In 1940, the population of Washington was approximately 75000 people, followed by both Yamhill and Columbia with population at around 30 000 people. From 1940 to 1970, Washington’s population rose substantially reaching over 120 000 in 1970 while Yamhill and Columbia saw a slight growth in population of 45000 people and around 36000 people respectively.
From 1970 to 2000, the growth of population in Washington was dramatic reaching over 240000 people in 2000 while Columbia and Yamhill continued to rise gradually. The number of Yamhill’ population was estimated to nearly 75 000 and Columbia’s was over 60 000.