Protein Myth. Do plants have enough protein?

this topic was discussed  many, many times, but I have a habit to do a research on my own :) just to know more about an issue and at the same time to go on with my education ;)

The World Health Organization (WHO) recommends that we obtain 5% of our calories from protein. This would mean that if you were a man burning 3000 calories per day, you would need 38 grams of protein. Here's the math on how this 38 grams of protein is calculated.

more about a calculation read here

well, I've found this facts.

Food                              % Protein

Grains and Flours
Whole Wheat Flour            16
Oatmeal                            15
White Flour                       11
Brown Rice                         9
Cornmeal                           9
White Rice                          7

Starchy Vegetables
Peas                                 28
Black Beans                      27
Kidney Beans                    27
Corn                                 11
Cassava                           10
Potato                               8
Sweet Potato                     7

Green Vegetables
Spinach                  51
Broccoli                 42
Asparagus               42
Lettuce                  40
Onions                           32
Mushrooms                    12
Carrots                           10

Animal Products
Cottage Cheese              68
Beef                                53
Chicken                          46
Salmon                           43
Skim Milk                       39
Egg                                 32
Pork                                29
Cheddar Cheese             25
Whole Milk                     21
Human Milk              5

percentage of spinach protein is higher then in chicken :)

also the information about amino acids essential for humans  (as 8  out of 20 of them we cant produce from scratch within our own bodies)  are presented in this article