After registering a six-year high in the first quarter of 2006, Rosslyn, Va.-based NEMA's Lighting Systems Index declined 2.2.3% during the second quarter. As in the prior quarter, the topline index was bolstered by gains in domestic shipments of emergency lighting, fixtures, and fluorescent ballasts.

Despite the drop, NEMA reports that the overall level of domestic shipments remains healthy, as evidenced by the index's 4.6% gain from a year ago and 13% growth over the past three years.