Here is some UCLA and UCB data.
UCLA Waitlist 2022 common dataset.
Offers: 16979
Opt ins: 11169
Admits: 367
UCB Waitlist 2022 Preliminary from UC Conference:
Opt in: 4650
Admits: 48
You can see 2019-2021 data on this link: UCLA Class of 2026 Waitlist/Appeal Discussion
http://talk.qa.collegeconfidential.com/t/uc-berkeley-class-of-2026-waitlist-appeal-discussion/
Waitlist admits and yield vary from year to year so difficult to compare.