{
 "metric": "security-headers",
 "segment": "gb-medium-large",
 "anchor": "company",
 "label": "UK medium & large companies",
 "population": "UK medium & large companies",
 "states": [
  "strong",
  "partial",
  "missing"
 ],
 "quiet_failure_states": [
  "partial",
  "missing"
 ],
 "measurement": "Tier 3a; check `Strict-Transport-Security`, `Content-Security-Policy`, `X-Frame-Options` on the homepage response. Denominator: `has_web`.",
 "why_it_matters": "HSTS is what stops the first, downgradeable request; CSP is what limits the damage of injected script. Both are one-line changes, and both are commonly switched off silently by a framework upgrade or a proxy change.",
 "limits": null,
 "data_tier": "http_3a",
 "population_predicate": "has_web",
 "entity_type": "domain",
 "kind": "failure",
 "latest": {
  "day": "2026-08-13",
  "n": 766,
  "qf_pct": 71.54,
  "ci": [
   68.24,
   74.62
  ],
  "dist": {
   "strong": 28.46,
   "partial": 16.71,
   "missing": 54.83
  },
  "snapshot": "uk-companies-house-per600-seed20260728"
 },
 "series": [
  {
   "day": "2026-08-01",
   "n": 412,
   "qf_pct": 74.27,
   "ci": [
    69.84,
    78.26
   ],
   "dist": {
    "strong": 25.73,
    "partial": 19.9,
    "missing": 54.37
   },
   "snapshot": "uk-companies-house-per300-seed20260728"
  },
  {
   "day": "2026-08-03",
   "n": 427,
   "qf_pct": 72.83,
   "ci": [
    68.42,
    76.84
   ],
   "dist": {
    "strong": 27.17,
    "partial": 19.91,
    "missing": 52.93
   },
   "snapshot": "uk-companies-house-per300-seed20260728"
  },
  {
   "day": "2026-08-04",
   "n": 766,
   "qf_pct": 72.06,
   "ci": [
    68.78,
    75.12
   ],
   "dist": {
    "strong": 27.94,
    "partial": 16.58,
    "missing": 55.48
   },
   "snapshot": "uk-companies-house-per600-seed20260728"
  },
  {
   "day": "2026-08-05",
   "n": 768,
   "qf_pct": 71.09,
   "ci": [
    67.79,
    74.19
   ],
   "dist": {
    "strong": 28.91,
    "partial": 16.54,
    "missing": 54.56
   },
   "snapshot": "uk-companies-house-per600-seed20260728"
  },
  {
   "day": "2026-08-06",
   "n": 765,
   "qf_pct": 71.37,
   "ci": [
    68.07,
    74.46
   ],
   "dist": {
    "strong": 28.63,
    "partial": 16.73,
    "missing": 54.64
   },
   "snapshot": "uk-companies-house-per600-seed20260728"
  },
  {
   "day": "2026-08-13",
   "n": 766,
   "qf_pct": 71.54,
   "ci": [
    68.24,
    74.62
   ],
   "dist": {
    "strong": 28.46,
    "partial": 16.71,
    "missing": 54.83
   },
   "snapshot": "uk-companies-house-per600-seed20260728"
  }
 ],
 "license": "CC BY 4.0",
 "source": "https://quietfailures.com/datasets/security-headers/gb-medium-large"
}