Update README.md

Signed-off-by: Peter Sewell <Peter.Sewell@cl.cam.ac.uk>

README.md

@@ -24,7 +24,7 @@ in the sail branch of this [risc-v-isa-manual repository](https://github.com/rem
 The process to perform this inclusion is explained [here](https://github.com/rems-project/riscv-isa-manual/blob/sail/README.SAIL).
 There is also the newer [Sail AsciiDoctor documentation support for RISC-V](https://github.com/Alasdair/asciidoctor-sail/blob/master/doc/built/sail_to_asciidoc.pdf).
 
-This is one of [several formal models](https://github.com/riscv/ISA_Formal_Spec_Public_Review/blob/master/comparison_table.md) that were compared within the
+This is one of [several formal models](https://github.com/riscv/ISA_Formal_Spec_Public_Review/blob/master/comparison_table.md) that were compared within the 2019
 [RISC-V ISA Formal Spec Public Review](https://github.com/riscv/ISA_Formal_Spec_Public_Review).