condition mean min max ZT0-3 2.21747 1.917285 2.77398 ZT4-7 0.6885319999999999 0.6885319999999999 0.6885319999999999 ZT8-11 2.3092050000000004 2.3092050000000004 2.3092050000000004 ZT12-15 2.226795 1.9935650000000003 2.460025 ZT16-19 2.8869350000000003 2.8869350000000003 2.8869350000000003 ZT20-23 1.8966599999999998 1.8966599999999998 1.8966599999999998