Unknown. There is a table "proportion of basic salary between men and woman by functional category" by no overall gender pay gap. (sustainability report 2017 p.41).

It's true that the proper figure is not reported. I think it could be figured out based on the % of women in each category alongside the proportion basic pay. For now though, I will change it to a value which is a crude average of employee categories, as it's a shame this effort to report comprehensively on the question results in an Unknown value.

(0.97+0.9+1.05+0.92+1+0.99)/6 = 0.9716 or 97.16%