Merchant Delivery Radius Segmentation

You are analyzing merchant service coverage for a food delivery platform. Given a table of merchants with their delivery radius in kilometers, segment them into three categories and count how many merchants fall into each. **Segments (using `delivery_radius` column):** - `'< 6'` — delivery_radius < 6 - `'6-10'` — delivery_radius >= 6 AND delivery_radius <= 10 - `'10+'` — delivery_radius > 10 **Output columns:** `delivery_radius_bucket`, `num_of_merchants` Return results ordered by segment sequence (`'< 6'` first, then `'6-10'`, then `'10+'`). Count all merchants regardless of active status.