i would say 2 monthly we no longer call if gate is locked front gets cleaned.for 50% to what ever you feel is right maybe 60% ish.
My business has flourished since i stopped calling i only have like 10 left which ill change too,
i just started turning up they said oh why didnt you call i just said sorry, continued working got paid turned up next time out did the front left a slip got a cheque turned up next time they were in with a smile on there face saying oh ill get the gate and everyone is happy and these were horrible when i used to call saying oh not tomorrow oh no not this time, lol