A farmer recorded the number of bushels of corn harvested from a specific plot of land for the first 5 years: 15, 18, 20, 22, and 25 bushels. In the sixth year, he harvested fewer than 10 bushels, and the average annual harvest for the six years was an integer. In the seventh year, he again harvested fewer than 10 bushels, and the average annual harvest for the seven years was also an integer. What is the absolute difference between the number of bushels harvested in the sixth and seventh years?
0
1
2
3
4
