Table 2: Standard deviations between two old catalogues and numbers of sampled stars N.

ID	epoch		137	964	1437	1572	1603	1689	1843
1	137		--	0.47	0.41	0.69	0.67	0.77	0.62
2	964		901	--	0.29	0.72	0.72	0.78	0.60
3	1437		860	861	--	0.66	0.68	0.72	0.55
4	1572	N	584	585	575	--	0.40	0.54	0.65
5	1603		709	706	699	593	--	0.59	0.65
6	1689		688	688	680	602	832	--	0.67
7	1843		792	793	780	644	878	952	--