condition mean min max ZT0-3 3.048717528 2.938959412 3.1584756439999997 ZT4-7 2.97538977975 2.537762549 3.4130170105 ZT8-11 4.95180611025 3.6321390635 6.271473157 ZT12-15 7.692204144 6.422681214 8.961727073999999 ZT16-19 9.03462200275 7.5690235805 10.500220425 ZT20-23 14.74266111 13.032351235 16.452970985