DHCP IP address range

When device gets IP address, it seems that the address is in the middle of the range.
Example with default settings : range start at 100 + 150 addresses : given address is 175
Example with specific settings : range start at 100 + 50 addresses : given address is 125

Usually, some other routers provide address starting at the bottom of the range.
Is there a reason why this “middle” behaviour is done ?

here is some info. Dnsmasq uses hash of MAC address to distribute IP address, so that the Ip address is the same for the same device. If dhcp gives sequential IP address, i.e. from the bottom of the range, when you device connected for a 2nd time and its IP address was occupied, it will get a different IP address.