Try this:
Year = 1995:2020;
Group = randi([2000 11000], size(Year));
figure
stem(Year, Group, 'filled')
lblc = sprintfc('%d',Group);
text(Year, Group+100, lblc, 'HorizontalAlignment','center', 'VerticalAlignment','bottom')
Make appropriate changes to the text and sprintfc calls to display the result you want. (The sprintfc function is undocumented, however uses the sprintf syntax. You can also use the compose function to produce a cell array of labels.)
