NEMA’s shipment index for sodium vapor high intensity discharge (HID) lamps increased 7.1 and 2.0% on a quarterly and year-over-year basis, respectively, during Q3 2011. However, metal halide lamps decreased by 5.3% from the previous quarter. The index for mercury vapor lamps decreased too, falling by 0.6% — erasing gains during the previous quarter. Moreover, the mercury vapor index posted a double-digit decline of 19.4% on a year-over-year basis.
Variations in market share were concentrated in sodium vapor and metal halide lamps. Sodium vapor lamps increased by 2.7% to 34.4%, while the market share of metal halide lamps decreased to 60.9%. The market share of sodium vapor lamps remained unchanged at 4.7%.