Post game stats, shields

So, I spent quite a while playing league and checking stats is a habit I believe most players possess. But, after spending some time playing champions like: Janna, Sona, Lux, Nautilus, Sion and so on, basically champions that employ shields, I started to wonder, how much they really do. I mean, we got healing done which is pretty much weird since most of characters do not have abilities that heal, but there is not shield value in post-game stats. Those values should be quite interesting i.e. to Janna mains, since she uses shields 24/7 or to Lux players, who can estimate how much they increase their team's sustain or "tankiness" during open teamfight. What do you think?

P.S.: There is actualy around 31 characters that employ mechanic to mitigate damage with shields or similar abilities (i.e. Sivir's spellshield, Shen's dodge)