condition mean min max ZT0-3 12.90665358 11.99876768 13.81453948 ZT4-7 12.176547812499999 11.036758045 13.316337579999999 ZT8-11 12.80218927175 11.2135075885 14.390870955 ZT12-15 12.6558181425 12.323176525000001 12.988459759999998 ZT16-19 12.319730601 10.379925292 14.25953591 ZT20-23 19.8866061775 18.152504280000002 21.620708075