Can someone explain wtf means this chart at btc.com , in particular what is the difference between Size and Size Count?
https://btc.com/stats/unconfirmed-tx?

Transaction FeesDistribution of Transaction FeesSizeSize Count
BTC/KvBSatoshis/vbytevbytesvbytes
>= 0.00400 >= 400
450450
< 0.00400 < 400
0450
< 0.00380 < 380
0450
< 0.00360 < 360
5771,027
< 0.00340 < 340
01,027
< 0.00320 < 320
867