Chemistry- electronegativity and bonding

[Dell]

the temperature for the following to reach a pressure of 100mmHg is as follows(celsius))

HI -> -72.1
HCl -> -114
HBr -> -97.7
HF -> -28.2

how can this be? since they are all combinations of H and an element of the last column before the noble gas surely the smaller the size of the molecule, the higher the temperature will be? since they are all a combination of H and an atom whose radius goes R=(F<Cl<Br<I) so the electronegativity goes (F>Cl>Br>I). surely the temp should go with the electronegativity??

 

[chemisttree]

It might be a combination of electronegativity, mass, hydrogen bonding, size, etc...