You have to subtract 3 from your bar y-values, then plot and re-label your y-axis:
xtl = {'4-2' '3-2' '3-2' '4-1' '3-1' '2-1'};
data = rand(6,3)+3;
figure(1)
hb = bar(data-3)
set(gca, 'XtickLabel', xtl)
set(hb(1),'FaceColor','c')
set(hb(2),'FaceColor','k')
set(hb(3),'FaceColor','r')
set(gca, 'YTick', [0:0.1:1], 'YTickLabel',[0:0.1:1]+3)
You will have to experiment with your data to work this in with it, but the techniques should be straightforward. Note that the 'YTick' values go from 0 to 1, but the labels go from 3 to 4. That’s the only ‘trick’ involved.