What Coins Circulated In Egypt In 1980?

During a visit to Egypt in 1984 I noticed that there were very few coins in circulation, yet a friend who had been there in 1980 had told me that many coins were in use.

From a brief perusal of "Krause" it seems that currency coins with the falcon obverse were issued in values of 1 mil - 10 piastres during 1972-3 followed by 2 and 20 piastres in 1980. There were also a lot of commemoratives.

So what was actually in circulation there in 1980? Did the 1 and 5 mils actually circulate to any degree? Were there any older coins around and how far back did they go? Why did they issue a 20pt piece in 1980 and why did everything apparently disappear from circulation sometime during the next 4 years?

I would welcome any information or comments.