condition mean min max ZT0-3 11.075544 11.075544 11.075544 ZT4-7 11.0150615 11.0150615 11.0150615 ZT8-11 9.902374 9.902374 9.902374 ZT12-15 10.1494985 10.1494985 10.1494985 ZT16-19 10.2638605 10.2638605 10.2638605 ZT20-23 9.3543175 9.3543175 9.3543175