condition mean min max ZT0-3 8.703136 8.703136 8.703136 ZT4-7 9.6082915 9.6082915 9.6082915 ZT8-11 12.0751145 12.0751145 12.0751145 ZT12-15 10.9285835 10.9285835 10.9285835 ZT16-19 9.653467500000001 9.653467500000001 9.653467500000001 ZT20-23 9.178968000000001 9.178968000000001 9.178968000000001