UK 20 Pence KM#939

https://en.numista.com/catalogue/pieces1376.html

Mintage data for this coin is incomplete and yet the field is locked. Please add the following data:

1985 74,274,000
1985 Proof 102,000
1986 167,000 In sets only
1986 Proof 125,000
1987 137,450,000
1987 Proof 89,000
1988 38,038,000
1988 Proof 125,000
1989 132,014,000
1989 Proof 100,000
1990 88,098,000
1990 Proof 100,000
1991 35,901,000
1991 Proof —
1992 31,205,000
1992 Proof —
1993 123,124,000
1993 Proof —
1994 67,131,000
1994 Proof —
1995 102,005,000
1995 Proof —
1996 83,164,000
1996 Proof —
1997 89,519,000 Variations in portrait exist
1997 Proof —

Many thanks - Rick

[Note to Admin.]
From 1985 to 1991 the head on the Obverse was a slightly smaller size
From 1993 to 1997 the head on the Obverse was a slightly larger size
 The change over was made part way through 1992 so there are two versions therefore
Is there a new or amended KM number starting 1992 e.g. KM#939a or KM#939.1 ?

I have both 1992 versions and add pictures ...

                    

Would be interesting to see those?! Krause & Mishler make no mention of a change to the obverse in 1992, but they do mention "varieties of portrait exist" for 1997 although they do not raise a separate KM# for this variation. Incidentally, KM#939a is a 1996 Silver Proof of this design.

I see you wrote that just before I was adding my two pictures above ! Seeing them as two separate pictures is a bit tricky, especially as the coins I show were made at different times; then again they do look different anyway for that reason (wearing etc.) plus my lighting could be better for them. So I put one on top of the other, side by side for the picture below, and it is easier to see the differences.
 On the left, the first (smaller head) version 1985 to 1992 can be seen where the lower right part of the portrait goes towards the edge - with it being smaller it is further away.
 Now I see them in one picture I also noticed that the first version has that part of the portrait more thinner or tapered. Then I see that the crown at the top is closer to the edge in the second (larger head) version.
 When I first heard about these a year or two ago I thought it meant there were just two versions of 1992 coin; then I read again that it was ALL 20p between '85-'97 dates. So anyone does not just have to look at a 1992 coin; for example if you compared a 1987 20p with a 1995 one you can spot the changes !

                                     

I added the data and your remarks about portrait variations to the obverse description of the coin
sheet. Images make it clear those exist. thanks for your help