condition mean min max ZT0-3 7.486838333333333 5.93929 8.66455 ZT4-7 3.614855 3.614855 3.614855 ZT8-11 5.0077300000000005 5.0077300000000005 5.0077300000000005 ZT12-15 9.636805 8.517575 10.756035 ZT16-19 8.67441 8.67441 8.67441 ZT20-23 9.838985000000001 9.838985000000001 9.838985000000001