NEMA’s shipment indexes for high intensity discharge (HID) lamps returned to positive growth territory during the first quarter of 2012, with each lamp type showing year-over-year gains following negative growth to close out the final quarter of 2011. Sodium vapor lamps increased 2.9 percent, while shipments of mercury vapor and metal halide HID lamps increased 5.0 and 0.1 percent, respectively.
 
Market shares varied slightly among the three lamp types. Sodium and mercury vapor lamps increased by 0.5 and 0.1 percentage points to 32.8 and 4.6 percent, respectively. Metal halide lamps posted a share of 62.5, a decline of 0.7 percentage points on a year-over-year basis.