The macrotrends link gets the gist correct, but for whatever reason, the way they scrape the data results in an incorrect share count for Apple for each 10K (each 9/30 date). Apple's share count doesn't stop falling and rise all of sudden each fiscal forth quarter. But the data presented in a 10K is a different format from a 10Q so somehow this site is scraping the wrong (not-comparable) figure for each fiscal Q4.

For reference, at 9/30/2022 Apple had 15,943,425,000 shares outstanding.

The most recent share count released (from the proxy) is 15,836,213,000 on 1/9/2023.

I believe the above figures indicate that Apple again slowed their share repurchase activity during a period it was seeing weakness in the business. The most popular iPhone model were supply constrained during the holiday quarter. The previous quarter (fiscal Q4), Apple repurchased over $25 Billion in stock. This looks like fiscal Q1 repurchase slowed from that pace. They have done this in the past when they are seeing a weak quarter. Unfortunately it often has the effect of slowing repurchase activity when the share price is lower and ramping it back up when the share price is higher.

I believe that puts Berkshire at 5.78% for what it's worth.

I've always been a fan of this document that Apple has put out consistently each quarter for a long time:
s2.q4cdn.com - Return of Capital Timeline
(this is a pdf from Apple's investor relations website)