I am working some takeoff and landing distance calculations for a 172 M Model. I have two versions of the T&L Charts.

One version of takeoff data has 4 columns across the top by altitude and temp: Sea Level 59F, 2500 50F, 5000 41F and 7500 32F (this is similar to 172L model data I have)

The other version of takeoff data has 5 columns across the top by temp: 0C, 10C, 20C, 30C and 40C (similar to charts I have for the P, R & S Models)

Can anyone tell me why the difference in formats for M model? And when it happened? I assume a format change happened somewhere around 1974, but I have not been able to confirm this.
Maybe I have the same, or similar, data that is just presented in different formats for some reason.