multi-plots

\documentclass[]{jlreq}
%\usepackage[letterpaper]{geometry}
\usepackage[top=0cm, bottom=0cm,left=0cm, right=0cm, paperheight=150mm]{geometry}
\usepackage[]{graphicx}

\usepackage{lipsum}
\usepackage{subcaption}

\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\pagestyle{empty}


\begin{document}
\begin{figure}[h]
\captionsetup[subfigure]{labelformat=empty}
\begin{subfigure}{.33\textwidth}
\centering
\begin{tikzpicture}
   \begin{axis}[,
    width=1.2\textwidth,
    ticks=none,
    axis y line=middle, axis x line=middle,
    enlargelimits={abs=0.1},
    xlabel={$x$},
    ylabel={$f(x)$},
    ylabel style={at={(ticklabel* cs:1.1)},anchor=north west},
    clip=false
    ]
    \draw (axis cs:0,0) node[below=5pt,right=-3pt] {$0$};
    \addplot[domain=-5:5,samples=100,very thick] {exp(-x^2/2)} node[below=5pt,right]{};
    \end{axis}
\end{tikzpicture}%
\caption{[1]}
\end{subfigure}%
\begin{subfigure}{.33\textwidth}
\centering
\begin{tikzpicture}
   \begin{axis}[,
    width=1.2\textwidth,
    ticks=none,
    axis y line=middle, axis x line=middle,
    enlargelimits={abs=0.1},
    xlabel={$x$},
    ylabel={$f(x)$},
    ylabel style={at={(ticklabel* cs:1.1)},anchor=north west},
    clip=false
    ]
    \draw (axis cs:0,0) node[below=5pt,right=-3pt] {$0$};
    \addplot[domain=-5:5,samples=100,very thick] {exp(-x^2/2)} node[below=5pt,right]{};
    \end{axis}
\end{tikzpicture}%
\caption{[2]}
\end{subfigure}%
\begin{subfigure}{.33\textwidth}
\centering
\begin{tikzpicture}
   \begin{axis}[,
    width=1.2\textwidth,
    ticks=none,
    axis y line=middle, axis x line=middle,
    enlargelimits={abs=0.1},
    xlabel={$x$},
    ylabel={$f(x)$},
    ylabel style={at={(ticklabel* cs:1.1)},anchor=north west},
    clip=false
    ]
    \draw (axis cs:0,0) node[below=5pt,right=-3pt] {$0$};
    \addplot[domain=-5:5,samples=100,very thick] {exp(-x^2/2)} node[below=5pt,right]{};
    \end{axis}
\end{tikzpicture}%
\caption{[3]}
\end{subfigure}%

\begin{subfigure}{.33\textwidth}
\centering
\begin{tikzpicture}
   \begin{axis}[,
    width=1.2\textwidth,
    ticks=none,
    axis y line=middle, axis x line=middle,
    enlargelimits={abs=0.1},
    xlabel={$x$},
    ylabel={$f(x)$},
    ylabel style={at={(ticklabel* cs:1.1)},anchor=north west},
    clip=false
    ]
    \draw (axis cs:0,0) node[below=5pt,right=-3pt] {$0$};
    \addplot[domain=-5:5,samples=100,very thick] {exp(-x^2/2)} node[below=5pt,right]{};
    \end{axis}
\end{tikzpicture}%
\caption{[4]}
\end{subfigure}%
\begin{subfigure}{.33\textwidth}
\centering
\begin{tikzpicture}
   \begin{axis}[,
    width=1.2\textwidth,
    ticks=none,
    axis y line=middle, axis x line=middle,
    enlargelimits={abs=0.1},
    xlabel={$x$},
    ylabel={$f(x)$},
    ylabel style={at={(ticklabel* cs:1.1)},anchor=north west},
    clip=false
    ]
    \draw (axis cs:0,0) node[below=5pt,right=-3pt] {$0$};
    \addplot[domain=-5:5,samples=100,very thick] {exp(-x^2/2)} node[below=5pt,right]{};
    \end{axis}
\end{tikzpicture}%
\caption{[5]}
\end{subfigure}%
\begin{subfigure}{.33\textwidth}
\centering
\begin{tikzpicture}
   \begin{axis}[,
    width=1.2\textwidth,
    ticks=none,
    axis y line=middle, axis x line=middle,
    enlargelimits={abs=0.1},
    xlabel={$x$},
    ylabel={$f(x)$},
    ylabel style={at={(ticklabel* cs:1.1)},anchor=north west},
    clip=false
    ]
    \draw (axis cs:0,0) node[below=5pt,right=-3pt] {$0$};
    \addplot[domain=-5:5,samples=100,very thick] {exp(-x^2/2)} node[below=5pt,right]{};
    \end{axis}
\end{tikzpicture}%
\caption{[6]}
\end{subfigure}%
\end{figure}

\end{document}