For most interventions these numbers is somewhere between 15 and 20 people treated for 10 years to prevent 1 event and only cholesterol lowering with statin close to 30 subjects. You may reduce risk by about 1/4, but if one starting risk is 30% that for it is lowering to 23% by intervention that implies, that something like 15 people need treating for that length of time of in the 14 are not going to benefit.