The data there is current in as much as there has been no general FM update or change since then. Only some planes have been going through some changes when they had been updated individually by HTC, latest example being the Hurricane. Others, like the La-7 had no or only minor performance changes. For most of the popular rides like 51's, Spitfires, 109's, 190s and so on the numbers are still up to date.
Of course, after five or six years, the newer fighters are missing entirely.