What will block provide?

My observe told me: Maybe block number is a percentage…
That may also explain why so little block value bonus in ICE section of citadel…
My shield told me he has 137 block value, and seems i take about 13.7% less damage from skulls when a block occur.
Anyone can confirm it? Or my thought was wrong?

That seems to be right.
And you add to it any Block Amount Bonus from gear with Solid (which shows as Block Damage Protection in battle)
And totally ignore the value from Citadel which may be broken?