question: As a former captain with extensive experience in the marine industry, list the top 5 busiest cargo ports in the world based on container traffic measured in TEUs (Twenty-foot Equivalent Units). Make sure your entire output is formatted as valid JSON.
answer: ```json
  {
    "busiest_ports": [
      {
        "rank": 1,
        "port_name": "Port of Shanghai",
        "country": "China",
        "container_traffic_TEUs": "47.0 million"
      },
      {
        "rank": 2,
        "port_name": "Port of Singapore",
        "country": "Singapore",
        "container_traffic_TEUs": "37.2 million"
      },
      {
        "rank": 3,
        "port_name": "Port of Ningbo-Zhoushan",
        "country": "China",
        "container_traffic_TEUs": "31.1 million"
      },
      {
        "rank": 4,
        "port_name": "Port of Shenzhen",
        "country": "China",
        "container_traffic_TEUs": "30.6 million"
      },
      {
        "rank": 5,
        "port_name": "Port of Guangzhou",
        "country": "China",
        "container_traffic_TEUs": "23.2 million"
      }
    ]
  }
  ```