condition mean min max ZT0-3 6.1881916666666665 4.519995 7.2106200000000005 ZT4-7 4.07642 4.07642 4.07642 ZT8-11 4.91572 4.91572 4.91572 ZT12-15 6.510785 6.49938 6.52219 ZT16-19 7.161495 7.161495 7.161495 ZT20-23 8.336665 8.336665 8.336665