condition mean min max ZT0-3 26.52725 24.513399999999997 28.5411 ZT4-7 32.4582 32.4582 32.4582 ZT8-11 27.30295 27.30295 27.30295 ZT12-15 0 0 0 ZT16-19 50.21455 50.21455 50.21455 ZT20-23 38.028400000000005 38.028400000000005 38.028400000000005