edit I don't need a solution anymore, I decided to not use the "negative" bars on the right side but I am leaving (and not deleting) this question in case someone else is looking for this in the future.
I'd like to produce this xbar plot style, where the two values obivously add up to the full 100%.

I already found a question named How to make a pgfplots stacked xbar plot with bar-“explicit meta” labels computed from input table data, but as far as I understood things it does not really help.
note Please do edit the title if you have a better phrase in mind for this question. I'm not a native speaker and couldn't think of a better description.
MWE of what I have so far:
\documentclass{scrartcl}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage{
pgfplots,
relsize,
sansmath
}
\begin{document}
\begin{center}
\begin{tikzpicture}[font=\sffamily\small\sansmath]
\begin{axis}[
height=7cm,
width=14cm,
%
xmin=0,
xmax=100,
%
ymin=2006,
ymax=2011,
%
xbar,
%
%axis lines*=left,
%
scaled y ticks=false,
y tick label style={/pgf/number format/1000 sep={}},
%
xlabel={Something in \%},
ylabel={Years},
%
legend style={at={(0.8,1.25)}},
legend columns=2,
legend cell align=left,
%
enlarge x limits=0.05,
enlarge y limits=0.1,
every axis x label/.style={
at={(ticklabel* cs:0.5)},
anchor=north,
yshift=-10pt
},
every axis y label/.style={
at={(ticklabel* cs:1.02)},
anchor=south,
text width=3cm
},
]
\addplot
[draw=black,fill=black!60]
coordinates
{(82.8,2011) (81.7,2010) (79.3,2009) (70.3,2008) (65.4,2007) (63.8,2006)};
\addlegendentry{abc}
\addplot
[draw=black,fill=white]
coordinates
{(17.2,2011) (18.3,2010) (20.7,2009) (29.7,2008) (34.6,2007) (36.7,2006)};
\addlegendentry{def}
\end{axis}
\end{tikzpicture}
\end{center}
\end{document}
Picture of what I have so far:

