Table 1. Delta-m Catalog Method Statistics 1 January 2012

---------------------------------------------+------+---------+--------------+
Method Description                           | Code |  Number | Mean Delta-m |
---------------------------------------------+------+---------+--------------+
Refractor, micrometer                        |  A   |     100 |     1.74     |
Reflector, micrometer                        |  B   |       0 |              |
Comparison image micrometer                  |  C   |     265 |     1.02     |
Heliometer                                   |  D   |       3 |     1.87     |
wide field CCD astrometry                    |  E   |   8,544 |     1.46     |
CCD astrometry                               |  F   | 158,098 |     1.61     |
Photographic, with astrograph                |  G   |      51 |     0.96     |
Photographic, medium or long-focus technique |  H   |   1,424 |     1.19     |
   includes ocular enlargement               |      |         |              |
Transit method                               |  I   |       0 |              |
Visual interferometer, aperture is of largest|  J   |     119 |     1.04     |
   baseline on the monolithic mirror (e.g.,  |      |         |              |
   Finsen's 26" or 240" on the 20 foot beam  |      |         |              |
   used on the 100")                         |      |         |              |
Long baseline interferometer                 |  K   |      72 |     1.65     |
   aperture is of largest telescope or       |      |         |              |
   siderostat not the baseline.              |      |         |              |
Electronographic camera                      |  L   |      40 |     1.98     |
Meridian circle                              |  M   |      57 |     1.41     |
Visual measures with double-image micrometer |  N   |     364 |     1.28     |
Lunar Occultation                            |  O   |     629 |     1.44     |
Photoelectric phase-grating interferometer   |  P   |     464 |     1.08     |
HST (FGS, WFPC, NICMOS, etc.)                |  Q   |      83 |     2.02     |
micrometer plus comparison image micrometer  |  R   |   3,873 |     1.47     |
Speckle interferometry                       |  S   |   4,762 |     1.54     |
Hipparcos or Tycho type observation          |  T   |   5,925 |     1.31     |
Adaptive Optics                              |  U   |   3,060 |     6.49     |
Photocell with diaphragm in focal plane      |  V   |     205 |     2.56     |
Area scanner                                 |  W   |   1,153 |     1.75     |
Visual estimate made with objective grating  |  X   |     316 |     0.24     |
Wedge photometer                             |  Y   |   4,124 |     3.27     |
double-image or polarizing photometer        |  Z   |   1,673 |     2.63     |
---------------------------------------------+------+---------+--------------+
Total                                                 195,530       1.71