Takes longer to download newer blocks?
There are a few different factors for the synchronization time:


You're not only downloading data, but the data is also being validated. There is a lot of I/O going on. Disk speed is a significant factor.
The earlier blocks are much smaller than the later blocks. Validation time roughly scales linearly with the data size.
Complexity of transactions may have increased over time, transactions with more inputs take significantly more time to validate.
The UTXO database grows larger as you parse the blockchain, and every input for every transaction has to be looked up in the UTXO database.