Treasury Bill rate at primary auction is keep rising

The Treasury bill yields have been rising faster phase as CBSL moving the cap rate (maximum rate for 364days Bills) continuously to encourage more bids for weekly T-Bill auctions. Even CBSL increased the 1Y cap rate continuously, it has not been a success so far to sell the required amount of T-bills to the public which results in more money printing. Since March CBSL has only managed to sell less than LKR 10Bn of 364Days Bills to the public that force CBSL to print the money or shift the borrowing to the short term.