condition mean min max ZT0-3 8.5293075 8.434425000000001 8.624189999999999 ZT4-7 9.15451 9.15451 9.15451 ZT8-11 9.59521 9.59521 9.59521 ZT12-15 0 0 0 ZT16-19 11.40595 11.40595 11.40595 ZT20-23 11.322 11.322 11.322