condition mean min max ZT0-3 15.55056 15.55056 15.55056 ZT4-7 17.814277500000003 17.814277500000003 17.814277500000003 ZT8-11 15.3544835 15.3544835 15.3544835 ZT12-15 13.566130999999999 13.566130999999999 13.566130999999999 ZT16-19 15.2120075 15.2120075 15.2120075 ZT20-23 17.0330175 17.0330175 17.0330175