\begin{table}[htb]
\caption{ overview of a selected and incomplete set of precision measurements at TLEP. Statistical errors have been calculated using the following assumptions: \\
1 year scan of the Z line shape with 50\% data at the peak, using resonant depolarization of single for energy calibration at O(20min)  intervals leading to $710^{11}$ Z decays ($M_Z,\Gamma_Z, R_{\ell} , N_{\nu}$ from peak cross-section, $R_b$). \\
1 year data taking with longitudinal polarized beams at 40\% beam polarization and luminosity reduced to 20\% of nominal (requires spin rotators).\\
1 Year data taking around 161 GeV (WW threshold scan) with resonant depolarization for energy calibration  at O(20min)  intervals ($M_W , N_{\nu}$ from ratio of $Z\gamma$ events with invisible Z vs leptonic Z decays).\\
5 years of data taking at 350 GeV (top threshold scan).
Systematic errors are only a “first look” estimate and will be revisited in the course of the design study.}
\label{EW precision table}
\renewcommand{\arraystretch}{1.} % enlarge line spacing 
\begin{tabular}{l c c c c c c c}
\hline
\hline
Quantity&	Physics	& Present precision & energy region &		TLEP
Stat  errors &	Possible TLEP
Syst. Errors	&TLEP key	&Challenge \\

\hline
\hline

\end{tabular}
\end{table}