condition mean min max ZT0-3 39.37435 34.494 44.2547 ZT4-7 26.62115 26.62115 26.62115 ZT8-11 36.83985 36.83985 36.83985 ZT12-15 0 0 0 ZT16-19 38.52955 38.52955 38.52955 ZT20-23 40.86905 40.86905 40.86905