condition mean min max ZT0-3 33.197071 33.197071 33.197071 ZT4-7 26.624859999999998 26.624859999999998 26.624859999999998 ZT8-11 25.063508 25.063508 25.063508 ZT12-15 29.579952000000002 29.579952000000002 29.579952000000002 ZT16-19 21.4457285 21.4457285 21.4457285 ZT20-23 18.388282 18.388282 18.388282