condition mean min max ZT0-3 10.091285 9.74107 10.4415 ZT4-7 15.1263 15.1263 15.1263 ZT8-11 16.83265 16.83265 16.83265 ZT12-15 0 0 0 ZT16-19 14.5711 14.5711 14.5711 ZT20-23 10.90425 10.90425 10.90425