condition mean min max ZT0-3 311.174412 311.174412 311.174412 ZT4-7 263.853999 263.853999 263.853999 ZT8-11 262.257215 262.257215 262.257215 ZT12-15 279.558606 279.558606 279.558606 ZT16-19 301.51505599999996 301.51505599999996 301.51505599999996 ZT20-23 267.39649599999996 267.39649599999996 267.39649599999996