Daily Price Limits (Limit Up Down) Explanation for Bonds

Can someone explain to me the limits for T-bonds. Yesterday I've already made a mistake of not buying T-bonds because I was afraid they were limit up (it looked like it, a certain price was reached and after that only horizontal dots and then it took off, I sold them on the way down though ),

The numbers on CME website don't make sense to me:
https://www.cmegroup.com/trading/interest-rates/us-treasury/30-year-us-treasury-bond_contract_specifications.html

scroll down to " Price Limit Or Circuit ", then download the excel file and it says for T-bonds (ZB)
Base in real economic value Level 1 Level 2 Level 3 Level 4 Level 5

$9000 900 1200 1500 1800 No Limit



So, what the hell are $9000 900 and 1200??? I understand in different markets the 7% or the 10% but these numbers don't make any sense whatsoever. 900 is 10% of 9000 but that's all my pattern recognition ability could master. I've never traded through a limit up/down market so before I do something stupid please explain, Thanks! And happy trading, these markets are amazing