[CQ-Contest] RBN question

[Tibor Finta]

Dear Experts,

I created a quick statistics sheet on RBN figures of the ARRL DX CW contest.
I took 4  SOSB 20M stations: HG0Y, HG5E, TM4W and UA9YBA.
Here is how many times they were spotted by RBN in North America:
HG0Y:  14236
HG5E:  16648
TM4W:  16223
UA9YBA: 4918

According to 3830scores.com and contestonlinescore.com pages these are the
QSO numbers:
HG0Y:   1005
HG5E:    902
TM4W:   1139
UA9YBA:  967

My question: how could it be that three stations were spotted by RBN three
times more than UA9YBA?
I listened to UA9YBA at the end of the contest and his CQ was absolutely
correct: "CQ UA9YBA UA9YBA TEST".

73:
Tibor
HG5E / HA1AH