Layer Estimates:

Layer: SF Tracts by Age (ID:0)
Count: 196
Extent:

XMin: -13704322.9849
YMin: 4536156.4617
XMax: -13617490.7939
YMax: 4560151.4075
Spatial Reference: 102100 (3857)

Layer: sf_healthdata.csv (ID:1)
Count: 195

Layer: sf_agedata.csv (ID:2)
Count: 197