for example, enter L = 200to return the ip-5 in the array
var arr = [
["IP-1", 0]
["IP-2", 13.995886423358685]
["IP-3", 68.39963953170276]
["IP-4", 138.76858428768008]
["IP-5", 149.30208981161982]
["IP-6", 834.9549765566625]
["IP-7", 1090.4950690761289]
["IP-8", 1247.927742934118]
["IP-9", 1310.497021041034]
["IP-10", 1956.925744992665]
["IP-11", 2270.413239030439]
["IP-12", 3337.6333001873586]
]