Trimmean function does not seem to work (with attached example)

Hi all,

I did a trimmean function and have a very strange result. My trimmean at the 50th percentile (cell b79) is lower than my trimmean at the 25th percentile (cell b78). Which is impossible since I only have have positive number and I know from another analysis the estimated results (see attached file). It drives me nuts, if somebody can have a look at it I would really appreciate it.

Thank you for your help,