\begin{table}%t1
\par
%\centering
\par
\caption{\label{table:1}Fit with seven parameters. Values of the parameters are given as well as the associated one-sigma error estimates.}  
\small \begin{tabular}{c c c c c c c c}  
\hline\hline  
Data  & $A_1$ & $B_1$ & $A_2$ & $B_2$ & $D$ & $C_1$ & $C_2$  \\  
   & $\sigma_{A1}$ & $\sigma_{B1}$ &$\sigma_{A2}$ & $\sigma_{B2}$ &$\sigma_D$&$\sigma_{C1}$&$\sigma_{C2}$  \\  
  & $\left({{{\rm ppm}^2}\over{\mu{\rm Hz}}}\right)$ & (s) & $\left({{{\rm ppm}^2}\over{\mu{\rm Hz}}}\right)$ & (s) & $\left({{{\rm ppm}^2}\over{\mu{\rm Hz}}}\right)$ &  &   \\    
\hline   \noalign{\smallskip}
   SPMb & 1.46 & 1297 & 0.60 & 444 & \phantom{.00}3 $\times 10^{-4}$ & 4.2 & 3.7   \\ 
        & 0.12 &   22 & 0.09 & 27  & \phantom{.0}8.6 $\times  10^{-3}$ & 0.4 & 0.5  \\ 
   SPMg & 0.69 & 1300 & 0.28 & 438 & \phantom{.00}4 $\times  10^{-4}$ & 4.4 & 3.8 \\
        & 0.10 & 41   & 0.07 & 50 & \phantom{.0}8.3 $\times  10^{-3}$ & 0.8 & 1.1 \\
   SPMr & 0.23 & 1320 & 0.09& 438 & \phantom{.0}$-2$ $\times  10^{-4}$ & 4.6 & 3.4  \\
        & 0.10 &  117 & 0.08& 185 & \phantom{.01}1 $\times  10^{-2}$ & 2.4 & 3.0  \\
   PMO6 & 0.54 & 1350& 0.13& 409 &  1.87 $\times  10^{-2}$ & 3.6 & 3.8 \\
        & 0.20 & 110  & 0.12& 156 &  1.20 $\times  10^{-2}$ & 1.6 & 3.0 \\
\hline     
\end{tabular}
\end{table}