condition mean min max ZT0-3 22.441447 22.441447 22.441447 ZT4-7 17.966746 17.966746 17.966746 ZT8-11 24.627568 24.627568 24.627568 ZT12-15 21.151204 21.151204 21.151204 ZT16-19 35.4864755 35.4864755 35.4864755 ZT20-23 28.622921 28.622921 28.622921