condition mean min max ZT0-3 10.475766 10.475766 10.475766 ZT4-7 11.4993245 11.4993245 11.4993245 ZT8-11 10.6797435 10.6797435 10.6797435 ZT12-15 9.813651 9.813651 9.813651 ZT16-19 9.9817085 9.9817085 9.9817085 ZT20-23 9.3652645 9.3652645 9.3652645