no doubt you had to have suffered through 2015 as an SSH. It's the only way that can be done, it's a cluster if not.
"oh i had tickets until 2, 5, 10 years ago and had them for x years..."

it'll be seniority based on years holding tickets as of now. given the size of the 2015 SSH base even if i didn't have any seniority i wouldn't exactly be worried. There are probably only 2k people in front of you worst case - you'll live.

my 2 cents.