In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: In the bolus group , 26 . 0 % ( 13 / 50 ) had akathisia compared with 32 . 7 % ( 16 / 49 ) in the infusion group ( Delta = - 6 . 7 % ; 95 % confidence interval [ CI ] - 24 . 6 % to 11 . 2 % ) .
### Output Text:
In the bolus group , 26 . 0 % ( 13 / 50 ) had akathisia compared with 32 . 7 % ( 16 / 49 ) in the infusion group ( Delta = - 6 . 7 % ; 95 % confidence interval [ CI ] - 24 . 6 % to 11 . 2 % ) . 