condition mean min max ZT0-3 21.675225 17.9554 25.39505 ZT4-7 8.923214999999999 8.923214999999999 8.923214999999999 ZT8-11 5.48266 5.48266 5.48266 ZT12-15 0 0 0 ZT16-19 8.642444999999999 8.642444999999999 8.642444999999999 ZT20-23 13.871200000000002 13.871200000000002 13.871200000000002