How do I plot the average and standard deviation of a specific variable of a file within several excel files?

Dear Community

Please help me with guidance.

I have a folder with many excel files and I found a way to load all that files in Matlab and read them.

The point is that, besides to load all these files, now I have to get plots where it shows the average and standard deviation of these measurements.

Inside of each folder, there are 9 measurements, where appears Voc (short circuit voltage), Isc, Pmmp, etc.

The objective is to plot the average of the 9 measurements, with the bars of standard deviation (Only Voc, for instance, that would be on Y axis) along the time (Like day 1, day 2, day 3, etc. on the X axis)

The last thing I couldn´t to make it. Please anyone help me with that, it´s a little complicated.

I send the script that I've made, and a picture of the example of the file.

Thanks a lot!

Voc=Clean(:,5);
tiempo=[]
a=1
t=a+1
t=length(Voc)
for i=1:t
    tiempo=[a,t]
end

[Walter Roberson]

Clean = {};

and in the loop,

Clean{k} = num;

After the loop you can process the values read in as needed.