During this time, the detector consisted of $5$ lines for most of $\rm 2007$ and $12$ lines from $\rm 2008$ to $\rm 2012$, with short periods of $\rm 8, 9$ and 10 lines.

The $\rm QFit$ and $\rm \Lambda Fit$ methods, as introduced in Section \[antares\], are respectively used for single- and multi-line track fit reconstructions. Pre-selection cuts are applied to obtain an event sample, dominated by well-reconstructed atmospheric neutrinos. For $\rm QFit$, only upgoing events are used, i.e. $\rm \cos(\theta_{rec}) > 0$. For $\rm \Lambda Fit$, the error estimate of the reconstructed muon track direction, $\beta$, should be smaller than $\rm 0.5$, and a cut $\rm \cos(\theta_{rec}) > -0.1$ is applied. The distributions of the track fit quality parameters, $\rm Q$ and $\rm \Lambda$, for the resulting event samples are shown in Figure \[qcutfig\] for both reconstruction methods. By choosing additionally the cuts $\rm Q < 0.8$ and $\rm \Lambda > -5.7$, a purity of $\rm 69$% and $\rm 72$% in muon neutrinos is reached for $\rm QFit$ and $\rm \Lambda Fit$, respectively. The zenith angle distributions of the event samples after the cuts in $\rm Q$ and $\rm \Lambda$ are shown in Figure \[costhcutfig\]. Single-line events, as reconstructed 