i don't think there are 500,000 scjp certification. sun searched two or three month ago generally for the 500,000th certification. because of this and many people get first scea then scjp and more later i think there are less than 300,000 scjp certifications in the world. scea? perhaps not more than 50,000!
subject: Statistics: SCJP, SCJD, SCWCD, SCBCD, SCDJWS and SCEA