Slower than I measured

[1a1a11a]

Hi there,
This is a great project, thank you!
I have been measuring latency between some of the regions using EC2 instances, somehow, you number is higher than mine (see below), any idea why?

us-east-2 <--> ca-central-1, mine: 24 ms, yours 42 ms.
us-east-2 <--> eu-central-1, mine: 96 ms, yours 115 ms.
similarly for us-east-1, mine is 20 ms smaller than yours.
I get similar numbers for the past month.