condition mean min max ZT0-3 13.460007 13.460007 13.460007 ZT4-7 13.444245 13.444245 13.444245 ZT8-11 10.8680965 10.8680965 10.8680965 ZT12-15 11.741392000000001 11.741392000000001 11.741392000000001 ZT16-19 10.951003 10.951003 10.951003 ZT20-23 11.282629 11.282629 11.282629