condition mean min max ZT0-3 17.160566666666668 13.5399 19.034950000000002 ZT4-7 11.985700000000001 11.985700000000001 11.985700000000001 ZT8-11 9.917415 9.917415 9.917415 ZT12-15 17.877399999999998 16.3861 19.368699999999997 ZT16-19 16.6702 16.6702 16.6702 ZT20-23 21.5379 21.5379 21.5379