condition mean min max ZT0-3 12.184053 12.184053 12.184053 ZT4-7 10.345154 10.345154 10.345154 ZT8-11 11.7286275 11.7286275 11.7286275 ZT12-15 10.6406305 10.6406305 10.6406305 ZT16-19 11.516134000000001 11.516134000000001 11.516134000000001 ZT20-23 11.335697 11.335697 11.335697