condition mean min max ZT0-3 68.563957 68.563957 68.563957 ZT4-7 69.748346 69.748346 69.748346 ZT8-11 87.987751 87.987751 87.987751 ZT12-15 77.707517 77.707517 77.707517 ZT16-19 88.633554 88.633554 88.633554 ZT20-23 87.255742 87.255742 87.255742