Producing the same-sized box plots for subfigures

I want to produce one figure consisting of 4 by 3 =12 subfigures in the same size, in which the figures in the first column only display the tile and y-axes labels. However, my current code produces a figure where the size of the figures in the first colum is different from the rest of columns.

How can I fix this?

% Just generating a random data to plot the box plots
% I referred to this link: https://ch.mathworks.com/help/stats/boxplot.html
x1 = rand(5,1);
x2 = rand(10,1);
x3 = rand(15,1);
x = [x1; x2; x3];

g1 = repmat({'One'},5,1);
g2 = repmat({'Two'},10,1);
g3 = repmat({'Three'},15,1);
g = [g1; g2; g3];

%%
for i=1:12
    subplot(4,3,i)
    boxplot(x,g)
    if i < 4
        title(label{j})
    end
    if mod(i,3)==1
        ylabel('Data');
    end
end

The output looks like this.

Answer 1

[Scott MacKenzie]

One approach is just to use a dummy y-axis label for the plots in the 2nd and 3rd columns:

if mod(i,3)==1
    ylabel('Data');
else
    ylabel(' '); % dummy y-axis label
end

Answer 2

[Cris LaPierre]

Since your y-axis labels are the same for all plots, consider using a tiled layout. I also use the newer boxchart function, which has slightly different syntax.

% Just generating a random data to plot the box plots
% I referred to this link: https://ch.mathworks.com/help/stats/boxplot.html
x1 = rand(5,1);
x2 = rand(10,1);
x3 = rand(15,1);
x = [x1; x2; x3];

g1 = repmat({'One'},5,1);
g2 = repmat({'Two'},10,1);
g3 = repmat({'Three'},15,1);
g = [g1; g2; g3];

%%
t = tiledlayout(4,3);
for i=1:12
    nexttile
    boxchart(categorical(g),x)
end
ylabel(t,'Data')
title(t,'360d')

[yp78]

Thank you for the nice suggestions!

I oversimplified my question; I actually needed to label y-axes differently for each row. I will follow your suggestion in other occasions :)