Bond order in ${\mathrm{O}}_2^{-}$ is ‘X’. Bond order in ${\mathrm{O}}_2^{2-}$ is ‘Y’. Sum of X and Y is

${\mathrm{O}}_2^{-2}-{\mathrm{KK}}^{\text{'}}{\left({\mathrm{\sigma }}_{2\mathrm{s}}\right)}^2{\left({\mathrm{\sigma }}_{2\mathrm{s}}^{*}\right)}^2{\left({{\mathrm{\sigma }}_{2\mathrm{p}}}_{\mathrm{z}}\right)}^2{\left({\mathrm{\pi }}_{2{\mathrm{p}}_{\mathrm{x}}}\right)}^2{\left({\mathrm{\pi }}_{2{\mathrm{p}}_{\mathrm{y}}}\right)}^2{\left({\mathrm{\pi }}_{2{\mathrm{p}}_{\mathrm{x}}}^{*}\right)}^2{\left({\mathrm{\pi }}_{2{\mathrm{p}}_{\mathrm{y}}}^{*}\right)}^2$

${\mathrm{O}}_2^{-}-{\mathrm{KK}}^{\text{'}}{\left({\mathrm{\sigma }}_{2\mathrm{s}}\right)}^2{\left({\mathrm{\sigma }}_{2\mathrm{s}}^{*}\right)}^2{\left({{\mathrm{\sigma }}_{2\mathrm{p}}}_{\mathrm{z}}\right)}^2{\left({\mathrm{\pi }}_{2{\mathrm{p}}_{\mathrm{y}}}\right)}^2{\left({\mathrm{\pi }}_{2{\mathrm{p}}_{\mathrm{y}}}\right)}^2{\left({\mathrm{\pi }}_{2{\mathrm{p}}_{\mathrm{x}}}^{*}\right)}^2{\left({\mathrm{\pi }}_{2{\mathrm{p}}_{\mathrm{y}}}^{*}\right)}^1$

Bond order :

$$\begin{gathered} {\mathrm{O}}_2^{2-}=\frac{10-8}{2} = 1 ; \\ {\mathrm{O}}_2^{-} =\frac{10-7}{2} =1.5 ; \end{gathered}$$