Some impressive times! There's obviously some self-selection here: Many people who don't exercise have no idea how long they could hold a plank, and people who are good at it are more likely to respond. These times are well above average:
"...your average college-aged female has a plank time of about 1 minute, 30 seconds, while an average college-aged male has a plank time of about 1 minute, 46 seconds (2). That said, you should know that most of these students were considered athletic to begin with, and they all volunteered for the study." (
https://physicalliving.com/how-long-should-i-hold-the-plank-exercise-for/)
I can do about 90 seconds but when I was doing more exercise I worked up to 2 minutes, then moved to other more intense exercises, which is the guidance I'd read. That is, if you can do more than 2 minutes, a plank isn't challenging enough. 51 year old male.