\begin{table}%T3
%\centering
\par
\caption{Sensitivity of line equivalent widths to age (1--13~Gyr) and
  metallicity (${\rm [Fe/H]}=-1.7$ to $0.4$). $\Delta_{\rm [Fe/H]}$ represents the
  fractional change in [Fe/H] needed to produce a 10\% variation of
  the index value at the zero point (\Zsol,~12~Gyr).
  $\Delta_{\rm age}$ is the similar quantity computed with the age.
  $\frac{\Delta_{\rm age}}{\Delta_{\rm [Fe/H]}}$ is the ratio of fractional
  change in age to the fractional change in [Fe/H] required to produce the
  same change in the index value \citep{Worthey1994,Jones1995}.
  High absolute values correspond to high sensitivity to $Z$.  This quantity is
  evaluated around the (\Zsol,~12~Gyr) zero point.  The last column
  reproduces the values in Table 6 of \citet{Worthey1994} and in Table~2
  of \citet{Jones1995}.}
\label{table:deltaEW}
\begin{tabular}{lcccc}
\hline 
\hline\\[-3.2mm] 
Index & 
$\Delta_{\rm [Fe/H]}$ & $\Delta_{\rm age}$ & $\frac{\Delta_{\rm age}}{\Delta_{\rm [Fe/H]}}$ & 
$\left( \frac{\Delta_{\rm age}}{\Delta_{\rm [Fe/H]}} \right)_{{\rm \tiny{W,J}}}$\\[-3.2mm]\\ 
\hline
Fe5335                  & 0.41 & 0.75 & 1.8 & 2.8\\  
Fe5270              	& 0.42 & 0.74 & 1.8 & 2.3\\  
{\bf H$\gamma$\_Z}  	& 0.73 & 1.03 & 1.4 & \\     
Mg$_{\rm b}$             	& 0.55 & 0.56 & 1.0 & 1.7\\  
H$\delta_{\rm A}$         	& 0.16 & 0.14 & 0.9 & 1.1\\  
H$\gamma_{\rm A}$         	& 0.36 & 0.31 & 0.9 & 1.0\\  
H$\gamma_F$         	& 0.23 & 0.15 & 0.7 & \\     
H$\gamma$\_Vaz      	& --3.04 & --0.42 & 0.1 & \\   
H$\beta$            	& --1.62 & --0.26 & 0.2 & 0.6\\
H$\gamma$\_HR       	& 6.50 & --1.06 & --0.2 & 0.0\\
{\bf H$\gamma$\_VHR}	& 11.05 & --1.06 & --0.1 & \\  
\hline
\end{tabular}
\end{table}