timestamp,concurrent_sessions,widevine,playready,fairplay,vodrm
2024-06-01T20:00:00,125000,68750,18750,31250,6250
2024-06-01T20:30:00,142000,78100,21300,35500,7100
2024-06-01T21:00:00,168000,92400,25200,42000,8400
# timestamp = operator-local ISO-8601; DRM columns optional (derived from drm_mix if omitted)