How to group_by year in this type data in Ruby -

i want group year:

[{"_id"=>{"year"=>2013, "month"=>8}, "count"=>69605},  {"_id"=>{"year"=>2013, "month"=>7}, "count"=>60620},  {"_id"=>{"year"=>2013, "month"=>12}, "count"=>56026},  {"_id"=>{"year"=>2014, "month"=>5}, "count"=>55067},  {"_id"=>{"year"=>2014, "month"=>4}, "count"=>51313},  {"_id"=>{"year"=>2013, "month"=>11}, "count"=>48044},  {"_id"=>{"year"=>2014, "month"=>8}, "count"=>43802},  {"_id"=>{"year"=>2014, "month"=>1}, "count"=>40428},  {"_id"=>{"year"=>2014, "month"=>3}, "count"=>39564},  {"_id"=>{"year"=>2013, "month"=>9}, "count"=>35682},  {"_id"=>{"year"=>2013, "month"=>10}, "count"=>34073},  {"_id"=>{"year"=>2014, "month"=>2}, "count"=>32774},  {"_id"=>{"year"=>2014, "month"=>6}, "count"=>30772},  {"_id"=>{"year"=>2014, "month"=>9}, "count"=>17347},  {"_id"=>{"year"=>2014, "month"=>7}, "count"=>5319},  {"_id"=>{"year"=>2013, "month"=>6}, "count"=>4468},  {"_id"=>{"year"=>2013, "month"=>5}, "count"=>2978},  {"_id"=>{"year"=>2013, "month"=>4}, "count"=>2498},  {"_id"=>{"year"=>2013, "month"=>3}, "count"=>360},  {"_id"=>{"year"=>2013, "month"=>1}, "count"=>112},  {"_id"=>{"year"=>2012, "month"=>12}, "count"=>88},  {"_id"=>{"year"=>2013, "month"=>2}, "count"=>28},  {"_id"=>{"year"=>2015, "month"=>11}, "count"=>1}] 

could me?

try this

your_array.group_by{|a| a["_id"]["year"]}