Added a view `global_rates`

[micheles]

And some renaming. For share_small one gets

| mea       | sig       |
|-----------+-----------|
| 0.09273   | 0.21024   |
| 0.09235   | 0.20957   |
| 0.09066   | 0.20562   |
| 0.08775   | 0.19896   |
| 0.08411   | 0.19080   |
| 0.08007   | 0.18189   |
| 0.07173   | 0.16359   |
| 0.06088   | 0.13970   |
| 0.04858   | 0.11237   |
| 0.03622   | 0.08463   |
| 0.02536   | 0.06001   |
| 0.01682   | 0.04048   |
| 0.01058   | 0.02601   |
| 0.00637   | 0.01607   |
| 0.00369   | 0.00958   |
| 0.00201   | 0.00537   |
| 0.00105   | 0.00287   |
| 5.146E-04 | 0.00144   |
| 2.353E-04 | 6.800E-04 |
| 9.883E-05 | 3.000E-04 |
| 3.818E-05 | 1.258E-04 |
| 1.352E-05 | 5.121E-05 |
| 4.514E-06 | 2.108E-05 |
| 1.393E-06 | 8.492E-06 |
| 4.868E-07 | 3.734E-06 |
| 2.433E-07 | 2.122E-06 |

As expected, sig > mea, due to the large epistemic errors.