The box plot below shows the number of years that 44 schools have participated in an interschool swimming meet:
 A box and whisker plot is drawn using a number line from 0 to 10 with primary markings and labels at 0, 5, and 10. In between two primary markings are 4 secondary markings. The box extends from 1 to 6 on the number line. There is a vertical line at 3.5. The whiskers end at 0 and 8. Above the plot is written Duration of Participation. Below the plot is written Years.
 At least how many schools have participated for 6 years or more?
 6
 8
 10
 11