In fact, if you look at 20/9/5, you only get
'17-'18: Westbrook, cousins
'16-'17: Westbrook
Then you have to go back to '04-'05 to get to the last person to do it, and it was KG. He was also the only one to do it in '03-'04, and in '02-'03 it was KG and Webber. Then just KG again for the three year stretch from '99-'00 to '01-'02.
So it is really rare. Also, how good was KG?