Spark Open Source Streamgraph Topic Over Time Infographic

Data visualization infographic titled "Streamgraph Topic Over Time" using a TREND LINE (over time) adapted as a dominant small-multiples grid of layered streamgraph panels, each panel showing topic intensity across time with one clear outlier surge emphasized. The main visual should be a clean grid of 6 small streamgraph charts, each with sharp x-axis labels "Year 1", "Year 2", "Year 3", "Year 4", "Year 5", "Year 6" and y-axis label "Topic Volume (illustrative)" with visible tick marks at "0", "20", "40", "60", "80", "100". Highlight one surprising outlier panel with a bold annotation and stronger contrast. Include a top subtitle in English: "Small-multiples view of changing topic patterns with one unexpected spike". Use realistic plausible illustrative numbers only, clearly marked as illustrative. Add 4 key insight callouts around the chart: 1) headline number "78" with text "Unexpected peak in one topic stream stands far above the grid baseline" and a small burst icon, 2) headline number "+42%" with text "Fastest rise occurs in the outlier panel during the middle period" and a small upward arrow icon, 3) headline number "6 panels" with text "Most streams stay stable while one pattern breaks the trend" and a small grid icon, 4) headline number "24" with text "Typical stream level remains clustered well below the standout surge" and a small wave icon. Add a small footer strip reading "Data note: Illustrative example. Figures shown are illustrative and not sourced unless specified by the user." Ensure no misleading axis truncation or scale manipulation; use a full zero baseline where appropriate and consistent scales across all small multiples. Visual style: retro 1970s magazine charts, editorial blue and cream palette, muted navy, powder blue, teal, faded ink, warm cream paper background, subtle print texture, vintage editorial typography, geometric icons, balanced negative space, nostalgic but precise mood. Include editorial data journalism illustration, FT / Bloomberg-grade chart aesthetics, vector-clean infographic layout. All text MUST be written in English (array). Every heading, label, caption, legend and metric name in the image must be in English — not English. Spell each English word correctly using English characters and diacritics. Numbers stay as digits, no fake authoritative sources cited, no watermarks Numbers labeled "illustrative" unless the user supplied specific sourced data. No fake authoritative sources cited (do not invent "Source: Reuters 2025" — use "Illustrative example" instead). No misleading axis truncation or scale manipulation.