Having not played a vampire in ESO before, I created a character with which to experiment and to gain a better understanding of how it works.

The bonuses and penalties for vampirism are:

Stage 1/2/3/4
Reduced Health Recovery: 10%/30%/60%/100%
Additional Flame Damage Taken: 5%/8%/13%/20%
Increased Regular Ability Cost: 6%/10%/16%/24%
Reduced Vampire Ability Cost: 3%/5%/8%/12%

The bonuses and penalties for the Vampire Lord set are:

Stage 1/2/3/4
Additional Flame Damage Taken: 1%/2%/4%/6%
Increased Regular Ability Cost: 1%/2%/4%/6%
Reduced Vampire Ability Cost: 5%/10%/15%/20%

Do the two sets of statistic stack with each other giving the following?

Reduced Health Recovery: 10%/30%/60%/100%
Additional Flame Damage Taken: 6%/10%/17%/26%
Increased Regular Ability Cost: 7%/12%/20%/30%
Reduced Vampire Ability Cost: 8%/15%/23%/32%

If they don’t stack, then how do they combine, or does one take precedence over the other?