s or no s

[yppah]

Hi teachers:

Please help to see which one of the following expressions are correct and why. Thanks!

1) over three-year spa experience
2) over three-years spa experience
3) over three-years of spa experience
4) over three years spa experience

[curmudgeon]

'spa' is not right, should be 'span'

so... over a three year span of experience

or

over three years span of experience

[yppah]

thank you, curmudgeon, for the reply.
what I want to say is over three years expeirence of visiting spa facilities. So which one is correct?

[curmudgeon]

Ahh!!!thats different

Over three years experience visiting spas