Historical resource usage and load averages can be viewed using the "sar" utility, which should exist by default on all cPanel servers from the sysstat package. The stats are collected when sysstat runs from cron (/etc/cron.d/sysstat). If the crond service is not running, sysstat will not be able to collect historical statistics.
To view recent resource usage histories from sar, you can provide the path to the file that corresponds with the date of the stats. For example, if you wanted to view the load averages for your server from the 25th of the month, you would run this command:
[root@host ~]$ sar -r -f /var/log/sa/sa25
The command above uses the '-r' flag to specify that memory utilization information, and the '-f' flag to specify which sar file (day of the month) to read the data from. Note that sar may not have historical data for every day of the month.