The quotient F / G, where F is the number of spots and G the number of groups, can be considered as a numerical density of spots.

In the previous listings the daily and monthly averages of F / G have been tabulated. The treatment of the data has been similar to that of the Wolf numbers, and has been done independently. The only difference is that now days without spots are not included, so in the final series, the number of days without data is 15.7%.

In the first list, the columns correspond to the date, number of groups, standard deviation and number of observations included in the average. When n <3, s = 99.99 has been taken to avoid empty entries.

In the second list, the columns correspond to the month in the format "aaaamm", number of groups, and standard deviation.

It is interesting to note that in the descending branch of cycle 22, a period of 8 months is very marked, and its multiple is 16 months. The behavior is repeated in the descending branch of cycle 23, although in this case, the period is 11-12 months.