condition mean min max ZT0-3 1.63411 1.63411 1.63411 ZT4-7 1.112495 1.112495 1.112495 ZT8-11 1.3553950000000001 1.3553950000000001 1.3553950000000001 ZT12-15 0.849969 0.849969 0.849969 ZT16-19 1.94353 1.94353 1.94353 ZT20-23 1.428345 1.428345 1.428345