condition mean min max ZT0-3 9.315034999999998 8.850905 9.779164999999999 ZT4-7 8.769535 8.769535 8.769535 ZT8-11 6.4885850000000005 6.4885850000000005 6.4885850000000005 ZT12-15 0 0 0 ZT16-19 7.587 7.587 7.587 ZT20-23 8.005690000000001 8.005690000000001 8.005690000000001