condition mean min max ZT0-3 8.430205 8.430205 8.430205 ZT4-7 5.497225 5.497225 5.497225 ZT8-11 6.11253 6.11253 6.11253 ZT12-15 5.558235 5.558235 5.558235 ZT16-19 5.1490849999999995 5.1490849999999995 5.1490849999999995 ZT20-23 8.42846 8.42846 8.42846