condition mean min max ZT0-3 21.072438 21.072438 21.072438 ZT4-7 16.8628455 16.8628455 16.8628455 ZT8-11 15.3409455 15.3409455 15.3409455 ZT12-15 16.9995045 16.9995045 16.9995045 ZT16-19 12.469912 12.469912 12.469912 ZT20-23 10.873660000000001 10.873660000000001 10.873660000000001