Need help with Economic Class form

[elbore]

I need help filling out the form Economic class, question 11 Work Experience Part 4 - Years of experience. I have been a Database Administrator (DBA), NOC code 2172 for more than 10 years, and have worked in 5 diferents companies doing the same.
Should I put 4 years or more of experience in every diferent period of time?
Thanks for your help.