Finding trough points in a data series

Hi everyone.

I am trying to find two most significant trough values in a data series.
For finding the first one I used MIN(C6:C406), but finding second one proves to be more difficult.
I want to specify, I am don't to find the second minimum point.
If anyone has any suggestions it would be verry helpful.

I attached here a sample of my data.
In the graph you can see that there are several trough( Minimum "peak").
I can find only the most negative one.
data series.xlsx

Thank you