schlumberger limited and subsidiaries shares of common stock issued in treasury shares outstanding ( stated in millions ) .                                                  | issued | in treasury  | shares outstanding
balance january 1 2008                           | 1334   | -138 ( 138 ) | 1196              
shares sold to optionees less shares exchanged   | 2013   | 5            | 5                 
shares issued under employee stock purchase plan | 2013   | 2            | 2                 
stock repurchase program                         | 2013   | -21 ( 21 )   | -21 ( 21 )        
issued on conversions of debentures              | 2013   | 12           | 12                
balance december 31 2008                         | 1334   | -140 ( 140 ) | 1194              
shares sold to optionees less shares exchanged   | 2013   | 4            | 4                 
vesting of restricted stock                      | 2013   | 1            | 1                 
shares issued under employee stock purchase plan | 2013   | 4            | 4                 
stock repurchase program                         | 2013   | -8 ( 8 )     | -8 ( 8 )          
balance december 31 2009                         | 1334   | -139 ( 139 ) | 1195              
acquisition of smith international inc .         | 100    | 76           | 176               
shares sold to optionees less shares exchanged   | 2013   | 6            | 6                 
shares issued under employee stock purchase plan | 2013   | 3            | 3                 
stock repurchase program                         | 2013   | -27 ( 27 )   | -27 ( 27 )        
issued on conversions of debentures              | 2013   | 8            | 8                 
balance december 31 2010                         | 1434   | -73 ( 73 )   | 1361               see the notes to consolidated financial statements part ii , item 8 .
Question: what was the balance of shares at the end of 2008?
Steps: Ask for number 1194
Answer: 1194.0
Question: what was the balance of shares at the end of 2009?

Read the following texts and table with financial data from an S&P 500 earnings report carefully.Based on the question-answer history (if provided), answer the last question. The answer may require mathematical calculation based on the data provided.
schlumberger limited and subsidiaries shares of common stock issued in treasury shares outstanding ( stated in millions ) .                                                  | issued | in treasury  | shares outstanding
balance january 1 2008                           | 1334   | -138 ( 138 ) | 1196              
shares sold to optionees less shares exchanged   | 2013   | 5            | 5                 
shares issued under employee stock purchase plan | 2013   | 2            | 2                 
stock repurchase program                         | 2013   | -21 ( 21 )   | -21 ( 21 )        
issued on conversions of debentures              | 2013   | 12           | 12                
balance december 31 2008                         | 1334   | -140 ( 140 ) | 1194              
shares sold to optionees less shares exchanged   | 2013   | 4            | 4                 
vesting of restricted stock                      | 2013   | 1            | 1                 
shares issued under employee stock purchase plan | 2013   | 4            | 4                 
stock repurchase program                         | 2013   | -8 ( 8 )     | -8 ( 8 )          
balance december 31 2009                         | 1334   | -139 ( 139 ) | 1195              
acquisition of smith international inc .         | 100    | 76           | 176               
shares sold to optionees less shares exchanged   | 2013   | 6            | 6                 
shares issued under employee stock purchase plan | 2013   | 3            | 3                 
stock repurchase program                         | 2013   | -27 ( 27 )   | -27 ( 27 )        
issued on conversions of debentures              | 2013   | 8            | 8                 
balance december 31 2010                         | 1434   | -73 ( 73 )   | 1361               see the notes to consolidated financial statements part ii , item 8 .
Question: what was the balance of shares at the end of 2008?
Steps: Ask for number 1194
Answer: 1194.0
Question: what was the balance of shares at the end of 2009?
