Ten year age bands are fine for younger athletes but as you get older these bands need to be narrower (suggest 5 years) to allow for the more rapid degradation in performance expected at this age. Surely a 64 year old can’t be expected to compete at the same level as a 55 year old. So perhaps after the 45 to 55 band it should go to 55 - 60 and 5 year increments thereafter.