condition mean min max ZT0-3 621.503808 621.503808 621.503808 ZT4-7 546.9514055 546.9514055 546.9514055 ZT8-11 448.647746 448.647746 448.647746 ZT12-15 594.958878 594.958878 594.958878 ZT16-19 604.4176365 604.4176365 604.4176365 ZT20-23 659.330091 659.330091 659.330091