condition mean min max ZT0-3 11.169291 11.169291 11.169291 ZT4-7 9.789405 9.789405 9.789405 ZT8-11 9.6294485 9.6294485 9.6294485 ZT12-15 10.021239999999999 10.021239999999999 10.021239999999999 ZT16-19 11.442934999999999 11.442934999999999 11.442934999999999 ZT20-23 11.9995185 11.9995185 11.9995185