200 Watt power-Max?

 

I have a Dell power supply rated at 200 Watts. Forum members
have said that Dell does not rate their power supplies at the
maximum wattage level but at a mean average. What would the
maxmium wattage be for a 200 W if 200 W is the mean average? What is the safe maxmium Wattage limit for this power supply?
Is there a formula or table listing average mean and maxmium Wattage for different Dell power supplies? What would be a safe maxmium Wattage load in % for any power supply?

 

Thanks