Per-metric % change over the requested lookback window for a specific market.
Market condition ID
Lookback window: 1h, 24h, 7d, 30d, 1mo, 1y (default: 24h)
Lookback window for /analytics/changes endpoints.
1h, 24h, 7d, 30d, 1mo, 1y Per-metric pct change
Per-metric % change. None when the window predates the entity's data
or the previous value was zero (division undefined).