Not sure why you are getting downvoted. It is certainly possible this is just an artifact of changing demographics, or even adoption of ICD-10. It could even be

Not sure why you are getting downvoted. It is certainly possible this is just an artifact of changing demographics, or even adoption of ICD-10. It could even be that birth records are becoming more reliable than in the past so people are not overstating their age as much (eg, to collect social security).