condition mean min max ZT0-3 10.75 10.75 10.75 ZT4-7 0.7 0.7 0.7 ZT8-11 14.7 14.7 14.7 ZT12-15 11.4 11.4 11.4 ZT16-19 13.450000000000001 13.450000000000001 13.450000000000001 ZT20-23 7.6 7.6 7.6