condition mean min max ZT0-3 25.224079 25.224079 25.224079 ZT4-7 27.79312 27.79312 27.79312 ZT8-11 38.1601625 38.1601625 38.1601625 ZT12-15 43.2473975 43.2473975 43.2473975 ZT16-19 28.6895095 28.6895095 28.6895095 ZT20-23 23.353211 23.353211 23.353211