Problem beim erstellen eines diagramms mit ca 9000 wertepaaren

\documentclass[a4paper,12pt]{scrreprt}

\usepackage[english,ngerman]{babel}
\usepackage{tikz}
\usepackage{pgfplots}
\begin{document}

\pgfplotsset{
 x tick label style={/pgf/number format/1000 sep=},
 y tick label style={/pgf/number format/1000 sep=}}
\usetikzlibrary{arrows, shapes}
\tikzset{>=stealth',}
\tikzstyle{block} = [rectangle, draw, 
    text width=13.5cm, text badly centered, rounded corners, minimum height=2em]
\tikzstyle{line} = [draw,thick,->]


\begin{figure}[h]
\centering
\begin{tikzpicture}
\begin{axis}[axis x line=bottom,
        axis y line=left,
        xlabel= {Zeit [s/200]}, 
        xmin=0,
        xmax=9500,
        xtick={0,1000,2000,3000,4000,5000,6000,7000,8000,9500},
        ylabel style={pH-Wert},
        ylabel= {pH-Wert},
        ymin=5,
        ymax=8,
        legend style = { at = {(0.9,0.3)}},
        width=\textwidth ,
        height=10cm]
\addplot[smooth,mark=none,color=red,thick] file {17VExpData.tex};
\legend{pH-Werte}
\end{axis}
\end{tikzpicture}
\caption[Diagramm der pH-Werte]{Diagramm den pH-Werte}
\label{k60a}
\end{figure}

\end{document}