condition mean min max ZT0-3 1.51464 1.51464 1.51464 ZT4-7 1.26635 1.26635 1.26635 ZT8-11 1.70024 1.70024 1.70024 ZT12-15 1.365875 1.365875 1.365875 ZT16-19 1.6600000000000001 1.6600000000000001 1.6600000000000001 ZT20-23 1.936105 1.936105 1.936105