Are Annual Congressional Pay Raises Constitutional?

A CNN reporter said that congress has raised its own pay nine times since 1997. If accurate, that would violate the 27th amendment which states, "No law varying the compensation for the services of the Senators and Representatives shall take effect until an election of Representatives shall have intervened." There have not been nine elections of Representatives since 1997, so how could they raise their pay nine times? We really need for someone with access to the facts to look into this. This amendment, written and submitted with the other ten amendments in the Bill of Rights, was clearly intended to prevent annual pay raises. In fact, the point was so that Congress could not vote themselves a pay raise without the voters a)being properly informed about it, and b)then having an opportunity to vote them out for doing it. I cannot see how they managed to find a constitutional way around the clear intent of the amendment.