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|View History:  Monthly  Annual Download Data (XLS File)               
|View History:  Monthly  Annual                                         
|View History:  Monthly  Annual                                         
|View History:                                                          
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|Illinois Natural Gas Underground Storage Capacity  (Million Cubic Feet)
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|Illinois Natural Gas Underground Storage Capacity  (Million Cubic Feet)
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|Year                                                                                                                              | Jan       | Feb       | Mar       | Apr       | May       | Jun       | Jul       | Aug       | Sep       | Oct       | Nov       | Dec      
|--------------------------------------------------------------------------------------------------------------------------------- | --------- | --------- | --------- | --------- | --------- | --------- | --------- | --------- | --------- | --------- | --------- | ---------
|2002                                                                                                                              | 898,565   | 898,565   | 898,565   | 898,565   | 898,565   | 898,565   | 898,565   | 898,565   | 898,565   | 898,565   | 898,565   | 898,565  
|2003                                                                                                                              | 898,565   | 898,565   | 898,565   | 898,565   | 898,565   | 901,274   | 901,274   | 901,274   | 945,307   | 945,307   | 945,307   | 945,307  
|2004                                                                                                                              | 959,244   | 959,244   | 959,244   | 959,244   | 959,112   | 959,112   | 959,112   | 959,112   | 959,112   | 972,388   | 972,388   | 972,388  
|                                                                                                                                 
|2005                                                                                                                              | 972,388   | 972,388   | 972,388   | 972,388   | 972,388   | 972,388   | 972,388   | 972,388   | 972,388   | 972,388   | 972,388   | 972,388  
|2006                                                                                                                              | 972,388   | 972,388   | 972,388   | 972,388   | 972,388   | 972,388   | 972,388   | 972,388   | 972,388   | 981,995   | 981,995   | 981,995  
|2007                                                                                                                              | 981,995   | 981,995   | 981,995   | 981,995   | 981,995   | 981,995   | 981,995   | 981,995   | 984,768   | 984,768   | 984,768   | 984,768  
|2008                                                                                                                              | 984,491   | 984,491   | 984,491   | 984,491   | 984,491   | 984,491   | 984,491   | 984,491   | 984,491   | 984,491   | 980,414   | 980,414  
|2009                                                                                                                              | 980,414   | 980,414   | 980,414   | 980,414   | 980,414   | 939,776   | 980,414   | 980,414   | 980,414   | 980,414   | 980,414   | 989,454  
|                                                                                                                                 
|2010                                                                                                                              | 989,454   | 989,454   | 989,454   | 989,454   | 989,454   | 989,454   | 989,454   | 989,454   | 989,454   | 989,454   | 989,454   | 989,454  
|2011                                                                                                                              | 989,454   | 989,454   | 989,454   | 989,454   | 989,454   | 989,454   | 989,454   | 989,454   | 989,454   | 990,487   | 990,487   | 990,487  
|2012                                                                                                                              | 997,355   | 997,355   | 997,355   | 997,885   | 997,355   | 997,355   | 997,355   | 997,355   | 997,355   | 997,355   | 997,355   | 999,931  
|2013                                                                                                                              | 999,931   | 999,931   | 999,931   | 999,931   | 999,931   | 999,931   | 1,000,281 | 1,000,281 | 1,000,281 | 1,000,281 | 1,000,281 | 1,000,281
|2014                                                                                                                              | 1,000,281 | 1,000,281 | 1,000,281 | 1,000,281 | 1,000,281 | 1,000,281 | 1,000,281 | 1,000,281 | 1,000,281 | 1,002,386 | 1,004,547 | 1,004,547
|                                                                                                                                 
|2015                                                                                                                              | 1,004,598 | 1,004,598 | 1,004,598 | 1,004,598 | 1,004,598 | 1,004,598 | 1,004,598 | 1,004,598 | 1,003,899 | 1,004,100 | 1,004,100 | 1,004,100
|2016                                                                                                                              | 1,004,100 | 1,004,100 | 1,004,100 | 1,004,100 | 1,004,100 | 1,004,130 | 1,004,130 | 1,004,130 | 1,004,130 | 1,004,330 | 1,004,210 | 1,004,410
|2017                                                                                                                              | 1,004,410 | 1,004,410 | 1,004,710 | 1,004,710 | 1,004,710 | 1,004,710 | 1,004,710 | 1,004,710 | 1,004,710 | 1,004,962 | 1,008,539 | 1,008,539
|2018                                                                                                                              | 1,008,549 | 1,008,549 | 1,008,849 | 1,008,849 | 1,008,849 | 1,008,849 | 1,008,849 | 1,008,849 | 1,008,849 | 1,008,979 | 1,009,080 | 1,009,080
|2019                                                                                                                              | 1,009,080 | 1,009,080 | 1,009,080 | 1,009,080 | 1,009,080 | 1,009,080 | 1,009,080 | 1,010,180 | 1,011,380 | 1,012,160 | 1,012,210 | 1,012,210
|                                                                                                                                 
|2020                                                                                                                              | 1,012,210 | 1,012,210 | 1,012,210 | 1,012,210 | 1,012,210 | 1,012,210 | 1,012,210 | 1,012,210 | 1,012,210 | 1,014,131 | 1,014,401 | 1,014,401
|2021                                                                                                                              | 1,014,401 | 1,014,401 | 1,014,401 | 1,014,401 | 1,014,401 | 1,014,401 | 1,014,401 | 1,014,401 | 1,014,401 | 1,014,902 | 1,018,292 | 1,018,292
|2022                                                                                                                              | 1,018,292 | 1,018,292 | 1,018,292 | 1,018,292 | 1,018,292 | 1,018,292 | 1,018,292 | 1,018,292 | 1,018,292 | 1,018,520 | 1,020,070 | 1,018,770
|2023                                                                                                                              | 1,018,770 | 1,018,770 | 1,018,770 | 1,018,770 | 1,018,770 | 1,018,770 | 1,018,770 | 1,018,770 | 1,018,770 | 1,018,973 | 1,019,173 | 1,019,173
|2024                                                                                                                              | 1,019,173 | 1,019,173 | 1,019,173 | 1,019,173 | 1,019,173 |           |           |           |           |           |           |          
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|- = No Data Reported;  -- = Not Applicable;  NA = Not Available;  W = Withheld to avoid disclosure of individual company data.
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|Release Date: 7/31/2024                                                                                                          
|Next Release Date: 8/30/2024