\begin{table}%t8
%\centering
\par
\caption{Difference between the slope of the index--$\sigma$ relation and the
expected index variation due to changes in the chemical composition.
\label{table-tripicco}}
\small
\begin{tabular}{@{}l rrrrrrrrrr@{}}
\hline\hline
Model & \multicolumn{1}{c}{$\Delta$CN$_2$}&\multicolumn{1}{c}{$\Delta$ Ca4227}&
\multicolumn{1}{c}{$\Delta$G4300}&\multicolumn{1}{c}{$\Delta$Fe4383}&
\multicolumn{1}{c}{$\Delta$Ca4455}&
\multicolumn{1}{c}{$\Delta$Fe4531}&
\multicolumn{1}{c}{$\Delta$C4668}&
\multicolumn{1}{c}{$\Delta$Fe5015}&
\multicolumn{1}{c@{}}{$\Delta$Mgb}&rms \\ 
\hline
 i    & $-0.109$ & 0.046  & $-0.050$ & 0.013 &0.032 & $-0.003$&$-0.054$ &  0.014 &0.110&0.040 \\
 ii   & $-0.148$ & 0.055  & $-0.068$ & 0.039 &0.030 & 0.004   &$-0.050$ &$-0.050$&0.092&0.045 \\
 iii  & $ 0.056$ &$-0.016$& $-0.008$ & 0.022 &0.029 &$-0.003$ & 0.035   & 0.014 & 0.098&0.029 \\ 
 iv   & $-0.002$ & 0.029  & $-0.019$ & 0.031 &0.033 &$-0.002$ & 0.006   & 0.026 & 0.006&0.023 \\
\hline
\end{tabular}
\end{table}