Complex sentence: It was initially home to Nos 1 and 25 Mirage squadrons, but since 1997 Nos 1 and 2 Mirage and F-16 squadrons have been based there.
Split into simpler sentences: It was initially home to Nos 1 and 25 Mirage squadrons. Since 1997 No's 1 and 2 (General Dynamics F-16 Fighting Falcon) squadrons have been based there.