sn74lvc2g14 vs sn74lvc1g14 - differing electrical characteristics

I'm looking at the single and dual schmitt-trigger inverters in the LVC series.  However, I notice that they have differing positive and negative going thresholds:

E.g. For Vcc = 3V:

These are quite different ranges given they are meant to be part of the same logic family!  I wanted to seek confirmation on if they really do differ, or if one set is possibly correct for both components.