The max value occurs when the server is processing something hard like entity visibility check or trace hull.
The chance of a function to take so long is so small that you can ignore it as Arkshine said.
Think that if you divide 0.733546 with 0.030394 you obtain something like 24.
So in 104069 calls a maximum of 24 are delayed so the number is too small if we compare them.
24/104069 = 2.31 * 10^(-4) this is the chance of a call to take so long. So it is too small.
Edit:
So yes it is normal for functions to lag randomly because the server has other stuff to process besides your plugin.