condition mean min max ZT0-3 10.469338 10.469338 10.469338 ZT4-7 8.9938585 8.9938585 8.9938585 ZT8-11 10.6077415 10.6077415 10.6077415 ZT12-15 9.6855715 9.6855715 9.6855715 ZT16-19 10.006421 10.006421 10.006421 ZT20-23 9.3235455 9.3235455 9.3235455