How is the Base Experience for a Monster Calculated in NM/Hell?

[Ohomemgrande]

I'm assuming that all I need to calculate the base experience that a monster gives is contained in monstats.txt

All of the information that I can find in the forums and guides seems to be related to the experience penalties and telling you what proportion of a monster's exp you'll get depending on relative level differences. I can't find anything that goes into the mechanics of how the base exp is calculated other than "check the german calculator" or look at the tables on Arreat Summit.

Has anyone taken a close look at this?

[Hrus]

If noratio is set to 0 or empty (it slmost allways is), values in MonLvl.txt are used for most stats as a base and it's multiplied by a percentage value from colums EXP, EXP(N),EXP(H) from MonStats.txt.

Example: Zombie in hell Blood Moor:
0) check MonStat.txt row zombie1, column noRation - empty (MonLvl.txt will be used)
1) Blood Moor is lvl 67
2) Check MonLvl.txt, row 67, column XP(H) = 26733
3) Check MonStat.txt, row zombie1, column EXP(H) = 105
4) EXP= 26733*1.05 = 28069 (Arreat Summit says the same number)
But Zombie in an area with different alvl gives different base EXP!