condition mean min max ZT0-3 3.2768100000000002 3.2768100000000002 3.2768100000000002 ZT4-7 3.6144499999999997 3.6144499999999997 3.6144499999999997 ZT8-11 6.234255 6.234255 6.234255 ZT12-15 9.172925 9.172925 9.172925 ZT16-19 9.237350000000001 9.237350000000001 9.237350000000001 ZT20-23 3.6307233333333335 3.6307233333333335 3.6307233333333335