condition mean min max ZT0-3 16.881069 16.881069 16.881069 ZT4-7 21.2733695 21.2733695 21.2733695 ZT8-11 23.177053 23.177053 23.177053 ZT12-15 23.9602155 23.9602155 23.9602155 ZT16-19 32.9405765 32.9405765 32.9405765 ZT20-23 36.287776 36.287776 36.287776