condition mean min max ZT0-3 18.4417 16.2387 20.6447 ZT4-7 11.93805 11.93805 11.93805 ZT8-11 10.010079999999999 10.010079999999999 10.010079999999999 ZT12-15 0 0 0 ZT16-19 12.72735 12.72735 12.72735 ZT20-23 14.60065 14.60065 14.60065