You can also change it in elementaldefs, globally
<!-- ** combat rating -> experience control ** -->
<CombatRatingToExpMultiplier>0.1</CombatRatingToExpMultiplier>
<!-- <StatPointsPerLevelUp>3</StatPointsPerLevelUp> (Obsolete) -->
<MaxExpFromCombat>-1</MaxExpFromCombat> <!-- set to -1 to disable -->
<MinExpFromCombat>1</MinExpFromCombat>
<MultiplierOnPointsToLevelUnit>1</MultiplierOnPointsToLevelUnit>
<ExpBaseOnPointsToLevelUnit>3.0</ExpBaseOnPointsToLevelUnit>
<ExpMultiplierOnDesignedUnits>0.5</ExpMultiplierOnDesignedUnits>
<UnitLevelUpPerkOfferCount>5</UnitLevelUpPerkOfferCount>
<CityLevelUpPerkOfferCount>5</CityLevelUpPerkOfferCount>
you can place elementsdefs in your mod folder too and it will work fine