condition mean min max ZT0-3 11.905574999999999 11.905574999999999 11.905574999999999 ZT4-7 6.56696 6.56696 6.56696 ZT8-11 3.8117349999999997 3.8117349999999997 3.8117349999999997 ZT12-15 6.091145 6.091145 6.091145 ZT16-19 14.5612 14.5612 14.5612 ZT20-23 14.38415 14.38415 14.38415