Choose report groups

${data.map(d=>`${d.name}`).join('')}

H1 2025 versus H1 2026. Classified Companies House charge instruments. Source: Commercial Mortgages Broker, Jan-Sep 2026 edition; charge snapshot 1 October. Groups are selected for illustration, not matched by size. No lending-value estimate.

`; const fmt=n=>n.toLocaleString('en-GB'),signed=n=>(n>0?'+':'')+fmt(n),pct=n=>(n>0?'+':'')+n.toFixed(1)+'%'; const inputs=[...root.querySelectorAll('input')];let selected=[]; function render(){ selected=data.filter(d=>inputs.find(i=>i.value===d.area).checked); const result=root.querySelector('.results'),download=root.querySelector('.download'); download.disabled=!selected.length; if(!selected.length){result.innerHTML='

Choose at least one report group to calculate a comparison. No areas selected; no growth rate is defined.

';return;} const a=selected.reduce((s,d)=>s+d.previous,0),b=selected.reduce((s,d)=>s+d.current,0); const weighted=100*(b-a)/a,equal=selected.reduce((s,d)=>s+100*(d.current-d.previous)/d.previous,0)/selected.length; result.innerHTML=`

${selected.length===7?'All seven groups: England and Wales':'Selected subset: '+selected.length+' of seven groups'}. ${selected.map(d=>d.name).join('; ')}.

Growth in combined charge count${pct(weighted)}${fmt(a)} in 2025 → ${fmt(b)} in 2026
${signed(b-a)} charges; weighted by 2025 counts.

Equal-weight mean of regional rates${pct(equal)}${selected.length===1?'The selected group has':'Each of the '+selected.length+' selected groups has'} a ${(100/selected.length).toFixed(1)}% weight.
${selected.length===1?'With one group, the two results coincide.':'Equal regional influence, regardless of starting count.'}

The weights behind the combined result

Each bar shows its share of the selected 2025 charge count, on the same 0% to 100% scale. These are count shares, not shares of lending value.

${selected.map(d=>`

${d.name}${(100*d.previous/a).toFixed(1)}%

`).join('')}

Check the counts and source reports

Rates use unrounded counts. Scroll the table horizontally on narrow screens.

${selected.map(d=>``).join('')}

H1 charge counts for selected groups
Report group	2025	2026	Change	Growth	Source
${d.name}	${fmt(d.previous)}	${fmt(d.current)}	${signed(d.current-d.previous)}	${pct(100*(d.current-d.previous)/d.previous)}	CSV
${selected.length===7?'England and Wales':'Selected subset total'}	${fmt(a)}	${fmt(b)}	${signed(b-a)}	${pct(weighted)}	Combined count

Combined calculation: 100 × (${fmt(b)} − ${fmt(a)}) ÷ ${fmt(a)} = ${pct(weighted)}. Equal-weight calculation: add the ${selected.length} unrounded regional rates and divide by ${selected.length}.

`; } inputs.forEach(i=>i.addEventListener('change',render)); root.querySelectorAll('[data-preset]').forEach(btn=>btn.addEventListener('click',()=>{inputs.forEach(i=>i.checked=btn.dataset.preset==='all'||(btn.dataset.preset==='pair'&&['london-and-south-east','wales'].includes(i.value)));render();})); root.querySelector('.download').addEventListener('click',()=>{ const total=selected.reduce((s,d)=>s+d.previous,0); const keys=['report_group','period','charges_2025','charges_2026','difference','growth_pct','prior_count_weight_pct','equal_weight_pct','report_url','source_csv_url']; const rows=selected.map(d=>[d.name,'H1',d.previous,d.current,d.current-d.previous,100*(d.current-d.previous)/d.previous,100*d.previous/total,100/selected.length,d.report,d.csv]); const csv=[keys,...rows].map(row=>row.map(v=>'"'+String(v).replaceAll('"','""')+'"').join(',')).join('\n'); const url=URL.createObjectURL(new Blob([csv],{type:'text/csv;charset=utf-8'}));const link=document.createElement('a');link.href=url;link.download='cmb-h1-regional-weighting-selection.csv';link.click();setTimeout(()=>URL.revokeObjectURL(url),1000); });render();return root; } display(regionalWeightExplorer(regionalChargeData));