condition mean min max ZT0-3 15.807925 15.7698 15.846049999999998 ZT4-7 6.456709999999999 6.456709999999999 6.456709999999999 ZT8-11 2.845185 2.845185 2.845185 ZT12-15 0 0 0 ZT16-19 10.790175 10.790175 10.790175 ZT20-23 12.88325 12.88325 12.88325