Method for updating Lead Rating Count on Custom Object

/*Method for updating Lead Rating Count on Custom Object names 'Configration'*/

1. public void leadRatingCount(Map<id,Lead> triggerNewMap)
2. {
3. Map<String,Integer> objMap=new Map<String,Integer>{'Hot'=>0,'Warm'=>0,'Cold'=>0};
4. for(Lead objLead:triggerNewMap.Values())
5. {
6. objMap.put(objLead.rating,objMap.get(objLead.Rating)+1);
7. }
8. Configration__c objConfigration=[select Hot_Leads__c,Warm_Leads__c,Cold_Leads__c from Configration__c limit 1];
9. System.Debug('Hot value '+objConfigration.Hot_Leads__c+'plus'+objmap.get('Hot'));
10. objConfigration.Hot_Leads__c +=objmap.get('Hot');
11. objConfigration.Warm_Leads__c +=objmap.get('Warm');
12. objConfigration.Cold_Leads__c +=objmap.get('Cold');
13. update objConfigration;
14. }