What do the status codes in a csv data download refer to?

When you download your LinkMachine link data in the form of a .csv file, the status of each link is represented in the file by a number. Here is a list of what status each number refers to:

No e-mail address = 0
E-mail not yet sent = 1
Exchange request sent = 2
Link exchange complete = 3
Link back missing = 4
Link back notice sent = 5
Removed = 6
Not yet reviewed = 7
Duplicate = 8
Irrelevent = 9
One way link = 30
InstantLink Exchange (Automatic, incoming) = 31
InstantLink Exchange (Automatic, outgoing) = 32
InstantLink Exchange = 33
Invitation sent (InstantLink) = 34
Invitation received (InstantLink) = 35
Link back reminder sent = 36
Exchange reminder sent = 37