A quick note:
That kink at the left end probably means your shadows are on the film's toe, and thus have less gradation (contrast), and thus need an extra boost. As Bill Burk suggested, shooting at a lower EI will lift the shadows off the toe where they'll get normal gradation. Also, some films have shorter toes than others and are more suitable for shadow-heavy scenes.

And I recommend XTOL. I've found it to be a terrific developer.

Mark Overton