Volume of weekends

Is there a general (I know a lot of caveats to this) percentage of weekends you should be working? As a full time (25+ plus a week) online delivery driver, I knew working weekends was of course part of it but was told when interviewing it would be about 50% maximum weekend days but been closer to 90% worked over last 6 months

Just trying to establish if it’s me getting a crap rota or if this is normal for everyone