Assuming you had a lengthly, gentle warmup prior to this test (20-30 minutes), it looks like your blood lactate crossed 2mmol/L somewhere around 170bpm, just a bit faster than 10km/h. Seems like a decent approximation of your aerobic threshold / VT1. If you’re following the Uphill Athlete zone system, that’d be the top end of Zone 2.
Anaerobic threshold, where lactate hits 4mmol/L, looks like it’s somewhere around 185bpm. A field test (how fast can you sustain for 30-60 minutes?) would also be useful to perform. I’m confused by the length of time of those test stages – looks like they varied from ~5 minutes to 10+ minutes?