"Circumvention" shall be defined as a change in the pattern of trade between third countries and the Community which stems from a practice, process or work for which there is insufficient due cause or economic justification other than the imposition of the duty, and where there is evidence that the remedial effects of the duty are being undermined in terms of the prices and/or quantities of the like products and there is evidence of dumping in relation to the normal values previously established for the like or similar products.