The lines on the graph track the total number of organ transplants completed annually (starting in 1988) for the 4 most active categories. The source of the data is the Organ Procurement and Transplantation Network (OPTN), the agency under contract with the U.S. government to maintain the national patient waiting list.
It is interesting to note the interruption in 2006 of the steady upward trend in all categories. All categories, except for heart, are on the decline. What happened??
Well, it seems that in the 2006 timeframe, "an endorsement of DCD (donation after cardiac death) by the Institute of Medicine followed by timely federal mandates issued by the Department of Health and Human Services and the Health Resources and Services Administration have bolstered the number of DCD transplants. Consequently, DCD has risen more than 10-fold over the past decade currently comprising >10% of all deceased donors. In contrast, donation after brain death (DBD) has reached a plateau and more recently has declined since 2006". See the entire American Journal of Transplantation article at the link provided below.
The answer to my question is somewhere in the detail of this article but I can't fully understand it. Why are fewer transplants being performed in spite of stable organ donation rates? Perhaps someone with better analytical skills than mine can shed some light on this worrisome trend.