Find standard deviation and plot mean of three dimensional matrix

I have image radiance data with pixel height (y) and width (x) of 150 and 120 at 151 wavenumbers (z) for each pixel. I need to find the mean radiance at each wavenumber and standard deviation. What am I doing wrong?

Data = 150x120x151 single

X = 1x151 double (wavenumbers)

StdDev=ones(1,151);
Mean=ones(1,151);
for counter=1:151
      StdDev(counter)=std2(Data(:,:,counter));
      Mean(counter)=mean(Data(:,:,counter));
end

    figure
    hold on
    plot(X,Mean,'k')
    plot(X,Mean(X)+StdDev(X),'r--')
    plot(X,Mean(X)-StdDev(X),'r--')
    hold off

I received this error:

In an assignment  A(I) = B, the number of elements in B and I must be the same.

Error in StdDevSSBare (line 34)
    Mean(counter)=mean(Data(:,:,counter));