condition mean min max ZT0-3 15.835352 15.835352 15.835352 ZT4-7 23.217559 23.217559 23.217559 ZT8-11 19.629276 19.629276 19.629276 ZT12-15 13.3099865 13.3099865 13.3099865 ZT16-19 13.697549500000001 13.697549500000001 13.697549500000001 ZT20-23 15.654461999999999 15.654461999999999 15.654461999999999