There were 50 or more warnings (use warnings() to see the first 50)
           used (Mb) gc trigger  (Mb) limit (Mb)  max used   (Mb)
Ncells  1491827 79.7    3404661 181.9         NA   3404661  181.9
Vcells 11853081 90.5   86411961 659.3      65536 168619641 1286.5
Quality: 998, with subgroup label: 977

=== USDA Order vs Subgroup on same KSSL+NASIS sample ===
Order:    n=998  top1=0.338  CI=[0.306, 0.367]
Subgroup: n=977  top1=0.024  CI=[0.014, 0.034]
