What is the order of bond enthalpies of halogens? Why is it not opposite to that of bond lengths?

Explanation

Bond lengths of halogens are in the order :
`F_2 < Cl_2 < Br_2 < I_2`
Bond energies are expected in the order:
`F_2 < Cl_2 > Br_2 > Cl_2`
But the experimental bond enthalpies are:
`Cl_2 > Br_2 > F_2 > I_2`.
Bond enthalphy of `F_2` is very less, because lone pair lone pair repulsions are appreciable in `F_2` as the bond lengths is small in `F_2`.
It was also throught, though not appropriate, that F- F bond is weak as multiple bond is not possible with no d-orbitals in the valence shell of fluorine.