condition mean min max ZT0-3 2.927145 2.927145 2.927145 ZT4-7 1.3897750000000002 1.3897750000000002 1.3897750000000002 ZT8-11 1.774975 1.774975 1.774975 ZT12-15 1.72393 1.72393 1.72393 ZT16-19 1.354384 1.354384 1.354384 ZT20-23 1.99892 1.99892 1.99892