Look at archived class pictures if you really want to know who lived in an area.
We tend to think today of "ethnic" as racial. The mid-Sunset I knew and loved was full of people of many ethnic backgrounds. Not sure your census data would capture the wonderful distinctions. My friends and classmates at Lawton in the 60's were from many varied backgrounds: post-WWII Greeks, Turks, Armenians, Palestinians, Israelis, Taiwanese, Japanese, Filipinos, Spanish, Portuguese, Russian, various Slavs, Arabs (we all must know one branch of the Dudum family!), Egyptians, plenty from various provicnes in China. There families with ancestors from Mexico and Nicaragua. There were kids from American Indian backgrounds, the India sub-continent.
I went into these people's houses (we used to do that back then) and had their sweets. I saw their old-world grandma's who made their soap from lard. I first had sweets from the Arab world in my friend Ricky Dudum's house. Mochi? First had it in 1967 at my friend Akiko's house. Watermelon soup? My friend Maichi Wong's mom made it for a party once. I was enthralled.
As for me, my family is from Hawaii. On very warm Indian Summer nights, my father would get his hibachi going, grill his teriyak chicken (before anyone knew what that was), and make chi-chi's for the whole block.
There was never a large black presence in the Sunset. But there were a few black families and as kids we played with who was available to play.