Table:
text: Historical mortality rates of puerperal fever
Monthly mortality rates for birthgiving women 1841-1849
Puerperal fever 
 mortality rates for birthgiving women at the first clinic at the 
 Vienna General Hospital 
 1841-1849 reported by 
 Semmelweis 
 . He devised and instituted a handwashing policy by mid-May 1847. His employment was terminated March 20, 1849
Month_ Births Deaths Rate_ Sort_restore
Sep 223 41 18.4 21
Okt 242 71 29.3 22
Nov 209 48 23.0 23
Dec 239 75 31.4 24
Jan 272 52 19.1 25
Feb 263 42 16.0 26
Mar 266 33 12.4 27
Apr 285 34 11.9 28
Maj 246 15 6.1 29
Jun 196 8 4.1 30
Jul 191 1 0.5 31
Aug 193 3 1.6 32
Sep 221 5 2.3 33
Okt 250 44 17.6 34
Nov 252 18 7.1 35
Dec 236 19 8.1 36
Jan 244 37 15.2 37
Feb 257 29 11.3 38
Mar 276 47 17.0 39
Apr 208 36 17.3 40
Maj 240 14 5.8 41

Question: What is the value that had deaths of 71 below the historical death rates from puerperal fever?