Here are the singles' peaks to date 
 
Mr Know it All (Release: 08/31/2011)
Australia #1  Current - 17th week
UK #4   Current  - 12th week
Bulgaria #7  Current  - 14th week
New Zealand #8  (14 weeks on chart)
World Chart #8   Current  - 15th week
US #10  Current - 17th week
Canada #11  Current  - 17th week
US Airplay #11  Current - 18th week
Ireland #14 (8 weeks on chart)
Germany #18  Current  - 10th week
Switzerland #22  Current  - 9th week
Austria #26  Current  - 10th week
What Doesn't Kill You (Release 11/14/2011 & 01/16/2012)
Australia #21  Current:- 6th week
New Zealand #26  Current:  - 5th week
Canada #64  Re-entry #74 - 2nd week
US #64 (2 weeks before single release)
UK #71  Debut #71 - 1st week
I'll Be Home For Christmas (Release: 12/02/2011)
US #93 (1 week)
Stronger Album
US: #2   Currently: #17  10 weeks on chart
Australia: #3  Currently: #20  11 weeks on chart
World: #4  Currently: #26 (re-entry)  7 weeks on chart
UK: #5  Currently: #59  11 weeks on chart
New Zealand: #6   Currently: #35  9 weeks on chart
Ireland #8  Currently: #71 (re-entry)  6 weeks on chart
Switzerland #12 (6 weeks on chart)
Germany #14 (2 Weeks on chart)
Netherlands #16 (6 weeks on chart)
Austria #20 (4 weeks on chart)
Sweden #39 (1 week on chart)
Spain #40 (2 weeks on chart)
Belgium #45 (1 week on chart)
Italy #68 (1 week on chart)
Mexico #85 (3 weeks on chart) 
 
Sales US: 451,000
Sales Worldwide: 750,000+
Certifications:
US: Gold
AUS: Gold
CAN: Gold
UK: Should be certified Gold soon since it has sold over 100,000 copies