Well if you're not doing something to attempt to lower you NOx while at the same AFR then you could get an AFR sensor and guestimate based on amount of leanness.
It's interesting the comparison of your two test sheets, the drop in the other number and increase in NOx shows that the ECU really leaned out.
Another thing I should mention is that I am currently using the FFT fuel additive. However, I make NO conclusions regarding emissions because I did not do a test of before/after adding the FFT. My tank was "already contaminated" with the stuff when I did my first smog test.
Once I run out of the FFT, I won't buy another because I did not see any significant change in my car's MPG or performance.