I'm surely stating the obvious here (I hope!), but what seems obvious for some people is not so for others.
Work Experience should not be expressed in years. There's a quality component to it that is more important than quantity. Some people learn very little over several years of "experience", while others learn and grow a lot in a fraction of the time.
The amount of experience is still important. And the quality of someone's experience is lot harder to measure, since it may depend on many interrelated factors: type of work done, intelligence, interest, motivation, attitude, the environment, and people (s)he worked with.
But please, don't measure experience in time units alone.
Unfortunately, if you need to hire someone, recruiters do little (if any) to find quality workers. They just care about keywords (like: java, web, manager) and the years of experience associated with each of them.
If you think about it, time is relatively easy to add to the experience of a person: it's just a matter of time :-).
The quality of a person's experience, on the other hand, depends a lot on his/her own will.