No Sentinel-2 L1C data available in 2015 and 2016

Hi

I'm trying to process Sentinel-2A L1C data back to 2015 and I'm finding that my STAC query is returning 0 datasets for 2015 and 2016. It does however return data from 2017 onward. According to the AWS database, the Sentinel-2A data archive goes back to June 2015 globally, so I'm just wondering why I don't see it with this query (see below). The code was adapted from here: https://odc-stac.readthedocs.io/en/latest/notebooks/stac-load-e84-aws.html

from pystac_client import Client


lon, lat = 146.39, -18.52

catalog = Client.open("https://earth-search.aws.element84.com/v1/")

# sentinel-s2-l1c
query = catalog.search(max_items=100,
                       collections=["sentinel-2-l1c"], 
                       datetime=["2015-01-01", "2016-12-31"],
                       intersects=dict(type="Point", coordinates=[lon, lat]),
)

items = list(query.items())
print(f"Found: {len(items):d} datasets")