I graduated within the top 5% of my class, from a top tier university in Canada. I had two years of co-op work experience, and a Master's degree. And it was no picnic for me to find my first job.
That was back in 1991, when about 70% of engineering grads in Canada worked as engineers.
As of 2011, only about 30% of engineering grads work as engineers.
I'd estimate that in Canada, roughly 1/2 the overall graduating class is falling into that disappointment category. They just had to find a job, so they did and moved on. Regrettably though, after two or more years out of the profession, your chances of getting back into it are near zero. Engineering education has a short shelf life.
The universities don't even bother to collect the stats on how many of their grads are appropriately employed- they don't care. The ask grads if they're employed, 6 months and 2 yrs after graduation, but don't ask if they're working in the field they were trained for. Instead they ask them a much vaguer question: whether or not their education was "relevant" to their job. Engineering grads are about as likely as the average of all university grads to be employed 6 months or 2 yrs after graduation. Of course that average includes such job magnet programs as fine arts, journalism etc.