[
  {
    "tier": "Low (0–25th percentile)",
    "zip_count": "8,106",
    "population": "16,124,299",
    "pct_population": "4.9%"
  },
  {
    "tier": "Moderate (25–50th)",
    "zip_count": "8,106",
    "population": "62,146,210",
    "pct_population": "18.8%"
  },
  {
    "tier": "Elevated (50–75th)",
    "zip_count": "8,107",
    "population": "94,546,540",
    "pct_population": "28.6%"
  },
  {
    "tier": "High (75–100th)",
    "zip_count": "8,109",
    "population": "157,704,896",
    "pct_population": "47.7%"
  }
]