fact_ks4_national_averages is computed once at dbt build time (covered by the EES DAG's stg_ees_ks4+ selector). _national_averages_payload now reads both national-averages marts instead of scanning the performance dataframe per year on every /api/compare request (~250ms saved per call). Fallback for the deploy-before-DAG window computes the latest year only. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_0146VHeLAWjDVE2B5uU67jCB