condition mean min max ZT0-3 19.17285 18.47665 19.86905 ZT4-7 17.4157 17.4157 17.4157 ZT8-11 14.293800000000001 14.293800000000001 14.293800000000001 ZT12-15 0 0 0 ZT16-19 14.698150000000002 14.698150000000002 14.698150000000002 ZT20-23 18.6554 18.6554 18.6554