ICU-20568 Correct the numberformatter.h docs for usage()
diff --git a/icu4c/source/i18n/unicode/numberformatter.h b/icu4c/source/i18n/unicode/numberformatter.h
index a4d0724..1ae9045 100644
--- a/icu4c/source/i18n/unicode/numberformatter.h
+++ b/icu4c/source/i18n/unicode/numberformatter.h
@@ -2102,8 +2102,8 @@
#ifndef U_HIDE_DRAFT_API
/**
- * Specifies the usage for which numbers will be formatted ("person",
- * "road", "person", etc.)
+ * Specifies the usage for which numbers will be formatted ("person-height",
+ * "road", "rainfall", etc.)
*
* When a `usage` is specified, the output unit will change depending on the
* `Locale` and the unit quantity. For example, formatting length
@@ -2777,4 +2777,3 @@
#endif /* U_SHOW_CPLUSPLUS_API */
#endif // __NUMBERFORMATTER_H__
-