Name	Last modified	Size	Description
	Parent Directory		-
	GN.zip	2020-04-14 14:50	80K	(whole directory together)
	GN.png	2020-04-14 11:55	43K	(bitmap as shown below)
	GN.pdf	2020-04-14 11:32	17K	Graph of yearly Group Number 1610-2015, vector version
	2GN.txt	2020-04-12 12:37	16K	data as printed from html and made one-column
	GN.gnp	2020-04-14 11:32	898	script in utf8, this is used for pdf version
	GN.gn	2020-04-14 11:31	891	script for pdf in il2
	GNpng.gnp	2020-04-14 11:54	870	script for png

Pro rok 2020 bude patrně průměrný údaj Group Number (počet skupin skvrn) opět téměř 0.
To lze odhadovat z jiného údaje, totiž počtu skvrn, viz http://www.sidc.be/silso/datafiles
Údaj Group Number uvedený v grafu je tam dostupný v http://www.sidc.be/silso/groupnumberv3

Graph in Czech (by Jenik Hollan, CzechGlobe; the texts in scripts are easy to be changed into another languages) from data in:

Svalgaard, L., Schatten, K.H.
Reconstruction of the Sunspot Group Number: The Backbone Method.
Sol Phys 291, 2653.2684 (2016). https://doi.org/10.1007/s11207-015-0815-8