condition mean min max ZT0-3 12.664535 12.664535 12.664535 ZT4-7 13.505745000000001 13.505745000000001 13.505745000000001 ZT8-11 15.710891499999999 15.710891499999999 15.710891499999999 ZT12-15 14.0175925 14.0175925 14.0175925 ZT16-19 15.012539499999999 15.012539499999999 15.012539499999999 ZT20-23 14.651565000000002 14.651565000000002 14.651565000000002