condition mean min max ZT0-3 29.757675 18.27435 41.241 ZT4-7 12.23162 12.23162 12.23162 ZT8-11 19.6839 19.6839 19.6839 ZT12-15 0 0 0 ZT16-19 39.78165 39.78165 39.78165 ZT20-23 23.6333 23.6333 23.6333