Often the numbers you read are from research of different sources. You might want to consider that research results will be different as it is taken from different research that won’t be the same just as individual people are different. You might think of it this way: Research results will show different outcomes due to the individuals who are studied having many differences on the whole for instance perhaps where they live. You won’t find the exact numbers of such things on the results of different research. For just one small example from a research project might be based on participants being primarily male with ages up to fifty and what were the participants exposed to, what known illnesses were present in their family members, etc. Research cannot include all participants who have exactly the same ancestors, background, other illnesses and exposures. Good research is going to show different results and new questions, but somewhere something will come up in research that can be useful. That may then lead us pointing into another direction to implement toward cause or cure.