condition mean min max ZT0-3 196.721377 196.721377 196.721377 ZT4-7 525.27292 525.27292 525.27292 ZT8-11 294.88698850000003 294.88698850000003 294.88698850000003 ZT12-15 411.27097200000003 411.27097200000003 411.27097200000003 ZT16-19 272.4145855 272.4145855 272.4145855 ZT20-23 369.0319435 369.0319435 369.0319435