This excerpt taken from the BEC 10-K filed Feb 26, 2007.
Current period constant currency revenue (see above) less prior year reported revenue
Prior year reported revenue
As discussed above in the Overview, we are undergoing a shift from STLs to OTLs. This increasing number of OTLs began negatively impacting revenue in 2005. Under OTLs the recognition of instrument revenue and earnings are spread over the life of the lease arrangement, which is typically five years. By contrast, under STLs the recognition of instrument revenue and earnings is at the inception of the lease. This shift impacted instrument related revenue within most product areas. Over the longer term, we expect this change to improve competitiveness and operating efficiency. While this change negatively impacted instrument revenue across many of our product lines, we continued to experience robust placements of our instruments which in turn drive growth in aftermarket consumables revenue. Consumables revenue across all product lines grew 10.4% in 2005 as a result of this large and growing installed base of systems and a greater average utilization of reagents.
A discussion of revenue by major product area for the year ended December 31, 2005 follows: