How many for which ? The number of incidents or the number of passengers who fall out or jump out ?
Let me tell you in advance that the statistics don't exist. Irrespective of my cynical nature, it is part of the reasons why Drivers and other staff see the dangers with Driver open. Its difficult to impossible to prove either way because the statistics aren't there to prove either.
The only thing we can say with certainty is that stop short and door releases happen. They could; prevent it and pretty much eliminate it overnight but due to costs and other factors, they won't.
Part of my previous comment is that technology like CSDE/SDO (correct side door enable/selective door operation) exist to specifically prevent these kind of incidents happening and as new stock is introduced and the technology is there to support the Drivers and help reduce incidents and increase safety, the arguments against DOO greatly diminish.
If you are prepared to accept Driver open, then you must accept that there will be a incident where someone opens it off the platform. That puts passengers at risk. Personally I do not accept that and support my colleagues in their decision to prevent the further rollout of DOO.