\begin{figure}[!htbp]
\begin{tikzpicture}
\pgfplotsset{
  % define a new style used for the plot used to add labels
  % 2 args means it takes two mandatory arguments, so must be used as
  % labelplot={first arg}{second arg}
  every axis/.style = {
        ybar stacked,
        bar width = 15pt,
        nodes near coords,
        enlarge x limits=0.3,
        ymin = 0,
        ymax = 110,
        legend style = {at={(0.95, 0.85)},
            anchor = east, legend columns = -1},
        ylabel = {Family clusters},
        symbolic x coords = {IT, Analytics, Business},
        xtick = data,
        x tick label style = {rotate = 45, anchor = east, yshift = -4pt},
    },
  labelplot/.style 2 args={
     % forget plot means it doesn't affect cycle lists or legends
     forget plot,
     % #1 is first argument, the text used in the nodes near coords
     nodes near coords=#1,
     % #2 is second argument, a length that should be the same as the bar shift for the axis
     every node near coord/.style={below,font=\tiny,xshift=#2}
  }
}
\begin{axis}[bar shift=-17pt, xticklabels={}]
\addplot coordinates
{(IT, 74) (Analytics, 19) (Business, 24)};
\addplot coordinates
{(IT, 26) (Analytics, 0) (Business, 26)};
\end{axis}
\begin{axis}
\addplot coordinates
{(IT, 15) (Analytics, 3) (Business, 18)};
\addplot coordinates
{(IT, 6) (Analytics, 0) (Business, 9)};
\end{axis}
\begin{axis}[bar shift=17pt, xticklabels={}]
\addplot coordinates
{(IT, 1) (Analytics, 44) (Business, 25)};
\addplot coordinates
{(IT, 42) (Analytics, 0) (Business, 14)};
\legend{\strut Core, \strut Options}
\end{axis}
\end{tikzpicture}
\caption{Families Per Course Bar Chart} \label{fig:familiesBarChart}
\end{figure}