diff --git a/chapter01.tex b/chapter01.tex
index 7d9609a..22b76bf 100644
--- a/chapter01.tex
+++ b/chapter01.tex
@@ -45,11 +45,11 @@ maintain them after the contest.
 
 At the moment, the most popular programming
 languages used in contests are C++, Python and Java.
-For example, in Google Code Jam 2016,
+For example, in Google Code Jam 2017,
 among the best 3,000 participants,
-73 \% used C++,
-15 \% used Python and
-10 \% used Java \cite{goo16}.
+79 \% used C++,
+16 \% used Python and
+8 \% used Java \cite{goo17}.
 Some participants also used several languages.
 
 Many people think that C++ is the best choice
diff --git a/list.tex b/list.tex
index 257b430..e138b9d 100644
--- a/list.tex
+++ b/list.tex
@@ -153,9 +153,9 @@
   A Guide to the Theory of NP-Completeness},
   W. H. Freeman and Company, 1979.
 
-\bibitem{goo16}
-  Google Code Jam Statistics (2016),
-  \url{https://www.go-hero.net/jam/16}
+\bibitem{goo17}
+  Google Code Jam Statistics (2017),
+  \url{https://www.go-hero.net/jam/17}
 
 \bibitem{gro14}
   A. Grønlund and S. Pettie.