condition mean min max ZT0-3 8.782575 8.782575 8.782575 ZT4-7 9.355933499999999 9.355933499999999 9.355933499999999 ZT8-11 8.423987499999999 8.423987499999999 8.423987499999999 ZT12-15 7.678652 7.678652 7.678652 ZT16-19 9.908327499999999 9.908327499999999 9.908327499999999 ZT20-23 9.565519 9.565519 9.565519