condition mean min max ZT0-3 24.428674 24.428674 24.428674 ZT4-7 10.294212 10.294212 10.294212 ZT8-11 8.902445 8.902445 8.902445 ZT12-15 9.5910875 9.5910875 9.5910875 ZT16-19 8.5764885 8.5764885 8.5764885 ZT20-23 9.21773 9.21773 9.21773