Graham03

I would like to pay for the following years, 2011/12 - £174.35, 2020/21 - £795.6 and 2021/22 - £800.8. When I try to do this online the only option it gives me which is close is 2020/21 - £795.6, 2021/22 - £800.8 and 2016/17 - £824.2, is there a reason why I cannot pay for 2011/12 as it's a smaller amount than for 2016/17? how do I go about paying for the years I want to pay? Thanks for your help.