The cost of eating out

I recently found this link on a message board (MMM), about Americans and dining out:

http://www.zerohedge.com/news/2017-07-26/first-time-americans-spend-more-eating-out-food-home

The graph shows that for the first time, Americans are spending more eating out than on groceries.  This doesn't surprise me at all.

I'll demonstrate:

I just got back from a week of vacation in Colorado.  We were in 2 hotels in 2 different cities.
- We got free breakfast at the hotel every morning.
- We had a mini-fridge in one hotel, and an efficiency kitchen at the other, so we had fruit, veg, and sandwich makings.
- We ate out 1 meal/ day or fewer.

- So meals out: 1. takeout pizza dinner.  2.  food truck Middle eastern sit-down lunch.  3.  Dinner out tacos/ burgers (only thing cheaper was the pizza)  4.  Dinner out pizza with friends.  5.  Very late lunch at a bistro.  6.  Ice cream.  7.  Burgers on the drive home from the airport

- Meals in: lunches: 6.  Dinners: 4  (there were 2 days we didn't eat out at all, had sandwiches for lunch and met our child-free friends at a park for a potluck so the kids could play).

So: 8 days. 6.5 meals out (ice cream is more of a snack), 10 meals "in" (groceries) and 7 meals free (breakfast)

Cost for 6.5 meals out: $292 = $45 each
Cost for 10 meals in: $100 = $10 each

That's more than 4x the cost to eat out than to eat something in the hotel room.  It doesn't take very many meals out for the cost of eating out to surpass the cost of groceries.

Total cost for the week for food: $400

The question is: what percentage of meals are "out"?