the willful bindness in hockey toward concussions has dropped什么意思

题目

the willful bindness in hockey toward concussions has dropped什么意思
The willful blindness in hockey toward concussions (头部撞击) has dropped.Hockey Canada has followed the lead of USA Hockey in preventing bodychecking (身体拦截) below age 13.A bad head injury of Sidney Crosby,the hockey's greatest star,opened the eyes of hockey people everywhere.This country's children have been facing similar danger at early ages,and Hockey Canada had to deal with a deep worry in the minds of Canadians to make the rule change.The liking for bodychecking from an early age is part of what makes Canadian hockey what it is.

答案

这个意思就是：
在曲棍球比赛中,发生恶意撞击对手头部事件的比率下降了.
你应该也结合上文看.