Statistics of sunspot activity
April, 1998
Visual indices of solar activity by author's observations
| Date | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | Average | % |
| W |   | 51 | 30 | 36 | 48 | 60 | 86 |   |   |   | 55 | 69 | 53 |   |   | 49 |   |   | 17 | 18 | 18 | 17 | 23 | 0 | 14 | 17 | 14 |   |   |   | 35.53 | 100 |
| Wn |   | 0 | 0 | 0 | 0 | 0 | 12 |   |   |   | 0 | 0 | 0 |   |   | 19 |   |   | 17 | 18 | 18 | 17 | 12 | 0 | 0 | 0 | 0 |   |   |   | 5.95 | 16.74 |
| Ws |   | 51 | 30 | 36 | 48 | 60 | 74 |   |   |   | 55 | 69 | 53 |   |   | 30 |   |   | 0 | 0 | 0 | 0 | 11 | 0 | 14 | 17 | 14 |   |   |   | 29.58 | 83.26 |
| n |   | 3 | 2 | 2 | 3 | 4 | 6 |   |   |   | 4 | 5 | 4 |   |   | 3 |   |   | 1 | 1 | 1 | 1 | 2 | 0 | 1 | 1 | 1 |   |   |   | 2.37 | 100 |
| A |   | 1 | 0 | 0 | 0 | 1 | 0 |   |   |   | 0 | 0 | 0 |   |   | 0 |   |   | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 |   |   |   | 0.16 | 6.67 |
| B |   | 0 | 0 | 0 | 0 | 0 | 1 |   |   |   | 1 | 1 | 1 |   |   | 0 |   |   | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |   |   |   | 0.21 | 8.89 |
| C |   | 0 | 1 | 0 | 2 | 0 | 0 |   |   |   | 1 | 2 | 2 |   |   | 2 |   |   | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 1 |   |   |   | 0.74 | 31.11 |
| D |   | 0 | 0 | 1 | 1 | 2 | 2 |   |   |   | 1 | 0 | 0 |   |   | 1 |   |   | 1 | 1 | 1 | 0 | 0 | 0 | 1 | 0 | 0 |   |   |   | 0.63 | 26.67 |
| E |   | 0 | 0 | 0 | 0 | 0 | 1 |   |   |   | 0 | 0 | 0 |   |   | 0 |   |   | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |   |   |   | 0.05 | 2.22 |
| F |   | 1 | 1 | 1 | 0 | 0 | 0 |   |   |   | 0 | 0 | 0 |   |   | 0 |   |   | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |   |   |   | 0.16 | 6.67 |
| G |   | 1 | 0 | 0 | 0 | 0 | 0 |   |   |   | 1 | 2 | 1 |   |   | 0 |   |   | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |   |   |   | 0.26 | 11.11 |
| H |   | 0 | 0 | 0 | 0 | 1 | 1 |   |   |   | 0 | 0 | 0 |   |   | 0 |   |   | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |   |   |   | 0.11 | 4.44 |
| I |   | 0 | 0 | 0 | 0 | 0 | 1 |   |   |   | 0 | 0 | 0 |   |   | 0 |   |   | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |   |   |   | 0.05 | 2.22 |
| x |   | 1 | 0 | 0 | 0 | 1 | 1 |   |   |   | 1 | 1 | 1 |   |   | 0 |   |   | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 |   |   |   | 0.37 | 15.56 |
| r |   | 0 | 0 | 1 | 0 | 0 | 1 |   |   |   | 0 | 1 | 0 |   |   | 1 |   |   | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 |   |   |   | 0.26 | 11.11 |
| s |   | 1 | 1 | 0 | 1 | 2 | 2 |   |   |   | 1 | 2 | 1 |   |   | 1 |   |   | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |   |   |   | 0.79 | 33.33 |
| a |   | 0 | 1 | 1 | 2 | 1 | 2 |   |   |   | 1 | 1 | 2 |   |   | 1 |   |   | 0 | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 0 |   |   |   | 0.74 | 31.11 |
| h |   | 1 | 0 | 0 | 0 | 0 | 0 |   |   |   | 0 | 0 | 0 |   |   | 0 |   |   | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |   |   |   | 0.05 | 2.22 |
| k |   | 0 | 0 | 0 | 0 | 0 | 0 |   |   |   | 1 | 0 | 0 |   |   | 0 |   |   | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |   |   |   | 0.16 | 6.67 |
| x |   | 1 | 0 | 0 | 0 | 2 | 2 |   |   |   | 0 | 0 | 0 |   |   | 0 |   |   | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 |   |   |   | 0.32 | 13.33 |
| o |   | 1 | 1 | 1 | 1 | 1 | 2 |   |   |   | 4 | 4 | 3 |   |   | 3 |   |   | 0 | 0 | 0 | 1 | 1 | 0 | 1 | 1 | 1 |   |   |   | 1.37 | 57.78 |
| i |   | 0 | 1 | 1 | 2 | 1 | 2 |   |   |   | 0 | 1 | 1 |   |   | 0 |   |   | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 |   |   |   | 0.63 | 26.67 |
| c |   | 1 | 0 | 0 | 0 | 0 | 0 |   |   |   | 0 | 0 | 0 |   |   | 0 |   |   | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |   |   |   | 0.05 | 2.22 |
| CV |   | 88 | 38 | 37 | 42 | 58 | 86 |   |   |   | 79 | 68 | 42 |   |   | 35 |   |   | 28 | 28 | 28 | 8 | 6 | 0 | 19 | 38 | 38 |   |   |   | 40.32 | 100 |
| CVn |   | 0 | 0 | 0 | 0 | 0 | 2 |   |   |   | 0 | 0 | 0 |   |   | 19 |   |   | 28 | 28 | 28 | 8 | 5 | 0 | 0 | 0 | 0 |   |   |   | 6.21 | 15.40 |
| CVs |   | 88 | 38 | 37 | 42 | 58 | 84 |   |   |   | 79 | 68 | 42 |   |   | 16 |   |   | 0 | 0 | 0 | 0 | 1 | 0 | 19 | 38 | 38 |   |   |   | 34.11 | 84.60 |
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