How to read buff uptime

Hi there, question’s in the title. If I select our latest log which took about half an hour, choose Encounters and Trash Fights and Friendlys -> my char, for buffs like mongoose potion and scorpok it shows like count:4, uptime: 3.63%. Obvsly I took only one of each and both held through to Nef, no wipes etc, so what does that tell me?

Also, my songflower ran out around chromie but DMT buffs held all the way through, but both show a count of 13 and percentage of 50.45. Is this actually a raidmember count with those buffs? Nothing to do with how long they were active/ upped on my char? Just can’t seem to get it. Thanks in advance for any explanation!