For certain difficult operations, a German hospital must prove its experience in numbers. The Federal Joint Committee, the G-BA, sets Mindestmengen, minimum numbers. A hospital may perform such an operation in the next calendar year only if its case numbers make it likely that it will reach the minimum. In December 2020 the G-BA raised two of them, with effect from 1 January 2021. For operations on the esophagus, the minimum rose from 10 to 26 a year at each hospital site, after a transition period. Hospitals caring for premature and newborn babies under 1,250 grams must now care for at least 25 such children a year instead of 14. For kidney transplants, the minimum of 25 a year stayed in place. The G-BA cited the scientifically demonstrable link between the number of operations and their quality. Particularly difficult planned operations should take place only in hospitals that have enough experience with them. The expected gain was fewer complications and deaths.