I have yet to allow update to Avast version 20.3, so I don't have the Stats section, but what information do you get if you click the little ! (more information) icon ?
Attacks prevented could be very varied and mean many things, but the only attacks I would be worried about would be those where Avast Alerted and presumably you haven't had any of those ?
Personally, a long time ago when the Statistics were previously in place, I rarely even looked at them, mainly because the data is historic, it has already happened. I don't really need avast to tell me how many attacks it has prevented, that is why I have it installed and if serious, surely it would have alerted.