What's funny about this is, in the original Dragon Ball Z script (the japanese one) the number was 8000 and not 9000, so for the hardcore Dragon Ball Z fans like me, it is 8000 and we already hit it a while ago. 9000 was just extra nice to see. Also not only in the japanese original version it is 8000, but in a lot of other languages it was dubbed as 8000 too.
https://www.youtube.com/watch?v=UNElg3th4KINappa: カカロットの戦闘力はいつくですか? [Kakarotto no sentoryoku ha itsuku desuka?] (Kakarot's battlestrength is how much?)
Vegeta: 8000以上だ!! [Hasseijou da!!] (8000 over!!)
Nappa: 八千以上?それは何か間違いだ!故障だ! [Hasseijou?! Sore ha nanika machikai da! Koshou da!] (8000 over?! That must be mistaken! Broken is!)
Nice trivia for DBZ nerds.