condition mean min max ZT0-3 21.943183333333334 19.7122 24.5494 ZT4-7 17.989649999999997 17.989649999999997 17.989649999999997 ZT8-11 17.7366 17.7366 17.7366 ZT12-15 9.530575 5.77225 13.288900000000002 ZT16-19 8.1654 8.1654 8.1654 ZT20-23 7.01893 7.01893 7.01893