condition mean min max ZT0-3 7.34327 7.34327 7.34327 ZT4-7 3.6658850000000003 3.6658850000000003 3.6658850000000003 ZT8-11 4.535705 4.535705 4.535705 ZT12-15 5.861525 5.861525 5.861525 ZT16-19 8.383980000000001 8.383980000000001 8.383980000000001 ZT20-23 10.9663 10.9663 10.9663