Update copyright

Author: jmh530

source/mir/math/stat.d

@@ -9,7 +9,7 @@ License: $(HTTP www.apache.org/licenses/LICENSE-2.0, Apache-2.0)
 
 Authors: Shigeki Karita (original numir code), Ilia Ki, John Michael Hall
 
-Copyright: 2020 Ilia Ki, Kaleidic Associates Advisory Limited, Symmetry Investments
+Copyright: 2020-3 Ilia Ki, Kaleidic Associates Advisory Limited, Symmetry Investments
 
 Macros:
 SUBREF = $(REF_ALTTEXT $(TT $2), $2, mir, math, $1)$(NBSP)