Well, try it and compare with the data.
To my eyes, just bonding and antibonding fits the given data nicely: increase up to N2, then decrease.
I've found interatomic distances: O2+ 132pm versus O2 121pm. Deduction?
Also, a triple bond may bring the nuclei closer than a double and a single, but each added bond is increasingly weaker nevertheless, if you think at H3C-CH3, H2C=CH2 and HC≡CH, so mind misleading ideas. Breaking at C≡C takes less than 1.5× than C=C which takes less than 2× C-C.
O, I see. The question wanted you to use the bond order.