gst eway bills national fy

All-India e-way bills from April to a given month of each fiscal year (GSTN national count), e.g. April-December, as the Economic Survey's Chart II.4b prints. Built from the same GSTN GST Day reports as gst_eway_bills_national. When the window's first months predate the oldest served report (April-May 2023), the window is GSTN's printed closed fiscal-year total less the later months (method 'fy_to