Metrics to determine health of your rentals?

[Brian Black]

I wanted to get a sense of what metrics you would find valuable in determining the overall health of your rental empire when tracks from a long-term perspective after purchase.

I look at:
NOI
Dollar per door
The average number of months rented
Vacancy rate
Cost of property management
Average APR of loans
Cap Rate
Equity/Value %
Maintenance costs

What else would you consider tracking in order to set goals and ensure the health of your rental pool?
What goals do you have for these metrics or others?
Other ways to ensure growth/improvement/quality/value?

THANKS!

BHB