condition mean min max ZT0-3 14.108375 12.981200000000001 15.23555 ZT4-7 11.07705 11.07705 11.07705 ZT8-11 7.662685 7.662685 7.662685 ZT12-15 0 0 0 ZT16-19 10.534105 10.534105 10.534105 ZT20-23 13.13055 13.13055 13.13055