JSFiddle - React, Tailwind, and code Playground

JavaScript

chaine = "(Timestamp: 14/01/2019 15:00; Average: 200)\
(Timestamp: 14/01/2019 15:05; Average: 200)\
(Timestamp: 14/01/2019 15:10; Average: 200)\
(Timestamp: 14/01/2019 15:15; Average: 200)\
(Timestamp: 14/01/2019 15:20; Average: 200)\
(Timestamp: 14/01/2019 15:00; Average: 200)\
(Timestamp: 14/01/2019 15:05; Average: 400)\
(Timestamp: 14/01/2019 15:10; Average: 200)\
(Timestamp: 14/01/2019 15:15; Average: 400)\
(Timestamp: 14/01/2019 15:20; Average: 400)";
 
reg1 = /\([^)]+\)/g;
 
temptab = chaine.match(reg1);
console.log(temptab);
reg2 = /\(Timestamp:\s([^;]+); Average:\s([^)]+)\)/
TAB = [];
temptab.map(function(a) {
  ttab = a.match(reg2);
  TAB.push({
    Timestamp: ttab[1],
    Average: ttab[2]
  });
});
 
 var i=-1;
 var tts=[];
 while (TAB[++i]) {
  if(TAB[i].Average != 200){
    tts.push( TAB[i].Timestamp )
  }
 }
 console.log(tts)