condition mean min max ZT0-3 8.8 8.8 8.8 ZT4-7 6.3 6.3 6.3 ZT8-11 30.15 30.15 30.15 ZT12-15 16.15 16.15 16.15 ZT16-19 9.100000000000001 9.100000000000001 9.100000000000001 ZT20-23 5.300000000000001 5.300000000000001 5.300000000000001