Changing plot axes proportions with split axes?

To plot notched box plots, I use:

x = [A_data B_data];

g = [zeros(length(A_data),1); ones(length(B_data),1)];

%boxplot(x, g)

figure;

boxplot(x,g,'Notch','on','Labels',{'A_condition','B_condition'})

xlabel('Data','FontSize',16);

ylabel('Y_Title','FontSize',16);

title('Figure title')

The y axis limits for these plots depend on the range of my data, but I would like to be able to change the proportions of the axis to better display the results. For example, instead of having a linear y axis from 0 to 30, I would like 70% of the y axis to show from 0 to 15, and 30% of the y axis to show from 15 to 30. This is different from an axis segmentation, where the axis may go from 0 to 15, break, then 25 to 30.

I have searched and I have not found a way to implement this in MATLAb (but it is easy to do in GraphPad Prism). Any ideas? Thank you.