condition mean min max ZT0-3 15.646208 15.646208 15.646208 ZT4-7 14.426110000000001 14.426110000000001 14.426110000000001 ZT8-11 14.289157 14.289157 14.289157 ZT12-15 11.961552999999999 11.961552999999999 11.961552999999999 ZT16-19 11.354785499999998 11.354785499999998 11.354785499999998 ZT20-23 12.2668725 12.2668725 12.2668725