(CNN) Apprehensions of families illegally crossing into the US from Mexico reached a record monthly high in October, the first month of the fiscal year, according to new Customs and Border Protection data released Friday.

The number of family members apprehended in October was 23,121, up almost 39% from September, which had 16,658 apprehensions -- a previous monthly record. This number is up 378% from last October, which had 4,836 family members apprehended.

CBP first began tracking apprehensions of family members in 2013.

Overall, the number is also continuing to climb, but is not close to a record. The total number of individuals apprehended illegally crossing the southwest border in October were 50,975, up from 41,486 in September and 25,488 last October. Historically, in the early to mid-2000s, there were months when well over 100,000 migrants were apprehended illegally crossing the southern border.

In October, 4,991 unaccompanied children were apprehended by border patrol along the southern border. Last October, more than 3,100 unaccompanied children were picked up after illegally crossing the southern border.

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