I'd reckon the following post war seasons are seasons where there was a serious danger of relegation
48-9 relegated
53-4 safe in the penultimate game
54-5 finished mid table after a woeful first 13 games (W2 D1 L10)
55-6 relegated
67-8 relegated
72-3 in trouble until around March , then did very well in the last 10 games (W6 D2 L2) to finish 14th
75-6 relegated
78-9 relegated
80-1 relegated
84-5 a woeful season, but there were thankfully 3 other even worse teams. Safe with 3 games to go
87-8 relegated
90-1 first win in game 17 and looking certs to go down. Then the astonishing post Xmas turn around sees us do 7 straight wins and finish 13th
91-2 Almost a repeat. Rock bottom in Nov. We then bear Wednesday and don't really look back to finish 9th.
92-3 struggling all season but win the last 3 and all but safe after the penultimate game.
93-4 relegated
95-6 awful start (5 straight defeats) and struggling until Bassett goes in Dec. Kendal has a slow start but gets into gear and wins 7 out of the last 9 as we finish 9th.
99-00. Awfull under Heath. Warnock takes over in Dec with us next to bottom. First 16 games sees us lose only 2 and we're safe by March. We then.fail to win any of the last 9 and finish 16th.
06-07 relegated
10-11 relegated
13-14 The disastrous Weir start sees us bottom. Clough comes in, starts slowly and were still struggling in Feb.. 7 straight wins sees us safe by mid March
20-21 relegated
23-24 relegated.
So that's 22 seasons where we struggled, 12 saw us go down, 8 we were comfortably safe well before the end of the season, 2 we took it more or less to the wire and stayed up.