In a small bowl, add yogurt, vinegar, garlic powder, salt and pepper. Whisk with a fork and set aside.
In a large salad bowl, add shrimps, tomato, cucumber, bell pepper, avocado and cilantro.
Pour dressing on top and mix gently to combine. Serve chilled.
Notes
Store: Refrigerate covered for up to 2 days (dressed is OK).
Make Ahead: Just leave out avocado and cilantro. Pour dressing on a side but do not stir. Or refrigerate dressing in a separate container and add before serving.
If using thick Greek yogurt, thin it out with a few tbsp of water.
Smaller sized shrimp is great for this salad as it's cheaper. If using large shrimp, cut in half.