Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Year of Issue | Weight | Diameter | Thickness | Edge |
| --- | --- | --- | --- | --- |
| 1976.0 | 3.24grams | 19.05mm | 1.42mm | Plain |
| 1977.0 | 1.87grams | 16.0mm | 1.35mm | Plain |
| 1979.0 | 2.80grams | 19.05mm | 1.38mm | Plain |
| 1979.0 | 2.70grams | 19.20mm | 1.30mm | Plain |
| 1980.0 | 2.3grams | 18.7mm | 1.3mm | Plain |
| 1981.0 | 2.6grams | 18.95mm | 1.5mm | Plain |
| 1981.0 | 2.5grams | 19.10mm | 1.45mm | Plain |
Question:
Which Diameter has a Year of Issue of 1977?
Answer:
16.0mm