documentclass{article}
usepackage{pgfplots}

begin{document}

begin{tikzpicture}
begin{axis}[
compat=newest,
ybar = 0.6,
width=1textwidth,
height=0.4textheight,
ymin=0,
ymax=100,
enlarge x limits = 0.1,
x axis line style={opacity=1},
bar width=20pt,
legend style={at={(0.5,-0.15)},
    anchor=north,legend columns=0},
ylabel={[%]},
symbolic x coords={A, B, C, D, E, F, missing},
xtick=data,
nodes near coords,
axis lines*=left,
y axis line style={opacity=1},
cycle list={
    {fill=black!60,draw=black!60},
    {fill=black!40,draw=black!40},
    {fill=black!20,draw=black!20}
},
axis on top,
legend style={draw=none,/tikz/every even column/.append style={column sep=0.5cm}}
]

addplot+[fill=black!10, text=black] coordinates {(A,62.5) (B,0) (C,4.5) (D,11.4) (E,14.8) (F,1.1) (missing,2.3)};
addplot[fill=black!70,text=black] coordinates {(A,15.0) (B,0) (C,5.8) (D,43.7) (E,18.4) (F,17) (missing,0)};

legend{sample X, sample Y}

end{axis}
end{tikzpicture}

end{document}