Can someone help me to centralize the elements of the clim / descent rate column? The dots and numbers have to be aligned vertically

\begin{tabular}{c  c  c  r@{}l r@{}l c }
\hline
Description &
Start Altitude &
End Altitude &
\multicolumn{2}{c}{Air Speed} &
\multicolumn{2}{c}{Climb/Descent Rate} &
\multicolumn{1}{c}{Distance}\\
\hline
Units & km & km & \multicolumn{2}{c}{m/s} & \multicolumn{2}{c}{m/s} & \multicolumn{1}{c}{km}\\
\hline
First Climb & $0.0$ & $2.0$ & $110$ & $.000$ & $6$ & $.0$ & $-$\\
Second Climb & $2.0$ & $4.5$ & $120$ & $.000$ & $6$ & $.0$ & $-$\\
Third Climb & $4.5$ & $5.0$ & $135$ & $.000$ & $3$ & $.0$ & $-$\\
Cruise & $5.0$ & $5.0$ & $135$ & $.278$ & $0$ & $.0$ & $1740.88$\\
First Descent & $5.0$ & $4.5$ & $130$ & $.000$ & $-4$ & $.5$ & $-$\\
Second Descent & $4.5$ & $4.0$ & $120$ & $.000$ & $-5$ & $.0$ & $-$\\
Third Descent & $4.0$ & $3.0$ & $115$ & $.000$ & $-5$ & $.0$ & $-$\\
Fourth Descent & $3.0$ & $2.0$ & $110$ & $.000$ & $-5$ & $.0$ & $-$\\
Fifth Descent & $2.0$ & $0.0$ & $100$ & $.000$ & $-3$ & $.0$ & $-$\\
\end{tabular}
\end{center}
\end{table}


With the help of the siunitx package and its S type columns, you can easily align numbers with respect to their decimal markers without using two columns:

\documentclass{article}
\usepackage{geometry}
\usepackage{booktabs}
\usepackage{siunitx}
\sisetup{per-mode=symbol}
\begin{document}
\begin{table}
\centering
\begin{tabular}{l
S[table-format=1.1]
S[table-format=1.1]
S[table-format=3.3]
S[table-format=-1.1]
S[table-format=4.2]}
\toprule
Description &
{Start Altitude} &
{End Altitude} &
{Air Speed} &
{Climb/Descent Rate} &
{Distance}\\
Units & \si{\km} & \si{\km} & \si{\m\per\s} & \si{\m\per\s} & \si{\km}\\
\midrule
First Climb    & 0.0 & 2.0 & 110.000 & 6.0  & {-}     \\
Second Climb   & 2.0 & 4.5 & 120.000 & 6.0  & {-}     \\
Third Climb    & 4.5 & 5.0 & 135.000 & 3.0  & {-}     \\
Cruise         & 5.0 & 5.0 & 135.278 & 0.0  & 1740.88 \\
First Descent  & 5.0 & 4.5 & 130.000 & -4.5 & {-}     \\
Second Descent & 4.5 & 4.0 & 120.000 & -5.0 & {-}     \\
Third Descent  & 4.0 & 3.0 & 115.000 & -5.0 & {-}     \\
Fourth Descent & 3.0 & 2.0 & 110.000 & -5.0 & {-}     \\
Fifth Descent  & 2.0 & 0.0 & 100.000 & -3.0 & {-}     \\
\bottomrule
\end{tabular}

\end{table}

\end{document}