condition mean min max ZT0-3 13.005455 13.005455 13.005455 ZT4-7 18.460908 18.460908 18.460908 ZT8-11 13.67725 13.67725 13.67725 ZT12-15 14.1697205 14.1697205 14.1697205 ZT16-19 14.233882000000001 14.233882000000001 14.233882000000001 ZT20-23 16.761502 16.761502 16.761502