After converting a file from WMA to MP3, I notice that in the ID3 tag produced by Lame it says the quality is "78 (V2 and q2)".

Was wondering what the number means, and how to change it?

This is exactly what it says when I right click on the file using Audio Identifier and click, Display Lame Tag.

Tag revision: 0
Version string: 3.97
Quality: 78 (V2 and q2)
Encoding method: vbr new / vbr mtrh
Lowpass: 18,600Hz
RG track peak: <not stored>
RG track gain: <not stored>
RG album gain: <not stored>
nspsytune: yes
nssafejoint: yes
nogap continued: no
nogap continuation: no
ATH type: 4
Bitrate: minimal (-b) bitrate 32
Encoder delay: 576 samples
Padded at end: 1,332 samples
Noise shaping: 1
Stereo mode: joint
Unwise settings: no
Source sample freq: 44.1kHz
MP3Gain change: <none>
Preset: V2: preset standard (fast mode)
Surround info: none
Music length: 5,121,277 bytes
Actual Music CRC: CCBD
Info tag CRC: 5799
Actual Info Tag CRC: 5799