Be aware, very old people die from this as a secondary cause from a primary of Alzheimer's and other dementias. They just stop eating. It's a misleading statistic to use to identify poverty based malnutrition. It's a very common diagnosis in terminal patients. And the way US billing works, getting the most diagnosis codes recorded is important for reimbursement. It's likely the cause for this disparity.

Edit: yeah 2015 is when ICD-10 adoption and cms billing changes went into play. And then the rate quadrupled. This is an artifact of the US's dumb private/public insurance model for end of life as more people gamed the system for reimbursement. The spread of billing practices over time.