According to today's AZ, Günter Hanft disarms around 20 WWII bombs throughout
Oberbayern every year, i.e. approximately one per fortnight. The rest of the time he's a fireman.
The bombs are almost never detonated. Rather, the detonator is removed and then the bomb can be safely carried away. Detonator removal usually takes about ten minutes. Or 20 minutes if it's badly corroded.
Also according to the AZ, around 8,000 tonnes of bombs were dropped on Munich during WWII. Assuming an average weight of 250kg per bomb, that makes a total of 32,000 bombs dropped.
Around 10% of the bombs dropped were duds. That makes about 3,200 that landed without exploding. Most of the duds were cleared up within weeks of being dropped. But the AZ reckons around 100 undiscovered UXBs are still buried beneath Munich.