What do P02/P01 and P1/P02 mean in a normal shock table?

[gfd43tg]

Hello,

I am wondering, on a Normal Shock Table, what are the two most right columns supposed to mean?

What is the ratio P02/P01 and P1/P02 supposed to be?

 

[boneh3ad]

$p_{02}/p_{01}$ is how the total pressure changes across the shock and is essentially a measure of how dissipative the shock is since total pressure loss is a result of the entropy gained across the shock.

$p_1/p_{02}$ is effectively just a ratio that is useful in some calculations.