What is the size of the baby jogging stroller market?  By "size" I
mean:
1) The number of baby jogging strollers currently in use (in the U.S.
and worldwide)
2) The number of baby jogging strollers sold per year (in the U.S. and
worldwide)
I am not interested in quantities of standard strollers, only jogging
strollers.  Jogging strollers are marked by having three wheels
instead of four and the wheels are larger than normal stroller wheels.
 I need to be able to verify the source of the answer that is
provided.