condition mean min max ZT0-3 1.6556600000000001 1.6556600000000001 1.6556600000000001 ZT4-7 1.549605 1.549605 1.549605 ZT8-11 1.46415 1.46415 1.46415 ZT12-15 1.742785 1.742785 1.742785 ZT16-19 2.47568 2.47568 2.47568 ZT20-23 2.22237 2.22237 2.22237