I took 9 times the GMAT before scoring a "decent" 650 (q:46-80%, v:34-72%)

I scored 470 two years ago, than at the end of 2005, when my company decided to support me, I enrolled to a GMAT prep course and finally I scored 650.

The problem is, how to justify these numerous tests? I'm applying to INSEAD and they require putting the number of tests I took.

I have 7 years of international management experience, top-1 Industry, a strong GPA, my company support for my applications, I think it should compensate this "non-stellar" GMAT.

I would use the additional essay to address this issue...saying that I have increased a lot my scores thanks to my commitment to enroll a top-mba school.

Any suggestions?

Thanks