condition mean min max ZT0-3 16.1309775 13.852805 18.40915 ZT4-7 20.4557 20.4557 20.4557 ZT8-11 13.562650000000001 13.562650000000001 13.562650000000001 ZT12-15 0 0 0 ZT16-19 16.74015 16.74015 16.74015 ZT20-23 15.033850000000001 15.033850000000001 15.033850000000001