condition mean min max ZT0-3 2.935815 2.2447 3.376105 ZT4-7 0.949023 0.949023 0.949023 ZT8-11 1.3067199999999999 1.3067199999999999 1.3067199999999999 ZT12-15 2.72592 1.620995 3.830845 ZT16-19 1.7946999999999997 1.7946999999999997 1.7946999999999997 ZT20-23 2.192995 2.192995 2.192995